All stories except for the initial one were presented in a serial format, with each serial being composed of two, 25-minute episodes. Created by Russell T Davies after a positive experience working with Elisabeth Sladen on the Doctor Who episode School Reunion, it concerned itself with Sarah Jane's life after her initial encounter with the Tenth Doctor. The series featured regular appearances by several teenaged cast members, their parents, a computer named Mr Smith, and K9. Aimed at a younger audience than Doctor Who, its UK timeslot was typically around 16:30 on Mondays and Tuesdays.
In its fourth year, it spawned a one-series, "clip show" spin-off of its own, named Sarah Jane's Alien Files. For 2010 only, there were some days where it was possible to find about an hour's worth of SJA programming on CBBC.
In celebration of the 10th Anniversary of the show, a special one-off event was held by a group known as "the Attic", to gather the cast and crew for celebration on 29th July 2017. Two months later, a selection of episodes were aired on 24 September 2017. In 2018 every episode was re-released on the BBC iPlayer.
The show followed Sarah Jane Smith sometime after she met the Tenth Doctor in School Reunion. Like UNIT and Torchwood, Sarah Jane had decided to deal with aliens in her own way. She was assisted by teenagers from her neighbourhood who unknowingly involve themselves in her life, such as Maria Jackson, Clyde Langer, and Rani Chandra. Also, through her adventures, Sarah Jane entered motherhood by adopting former alien-created tools, such as her son Luke Smith and daughter Sky Smith. She was assisted in knowledge of alien life and technology by her super-computer, Mr Smith and robot dog K9 Mark IV.
The series was set largely in and around Bannerman Road, Ealing — the street on which Sarah Jane lived. As shown in the initial, New Year's Day special, Sarah Jane was a somewhat wealthy and mostly reclusive eccentric. Her somewhat lavish house, car and lifestyle were paid for by her work as a freelance journalist, and an inheritance from the aunt established in her first Doctor Who appearance and the pilot for Sarah Jane's first spin-off series.
In the opening narrative, she acquired an adopted son, a highly-evolved human, who had been manufactured by the Bane. Her hitherto lonely life was also invaded by Maria, a girl who had just moved into the house across the road. Once the series proper began, and her adopted son, Luke, started attending school with Maria, they picked up a third friend, named Clyde Langer. Initially, then, the format of the series was about the three school-aged kids having alien-fighting adventures with Sarah Jane, whilst trying to keep Maria's divorced dad and mum unaware of their activities. Major subplots included: Maria and Alan Jackson's attempts to have a productive relationship with Chrissie, in the wake of the divorce; Sarah Jane's efforts to be a good mother; Clyde's attempts to help the socially awkward Luke "be cool"; the gradual uncovering of Mr Smith's true nature; and Alan's discovery of what exactly happened at Sarah Jane's house.
Early in series 2, however, the show obviously scaled back the importance of adults other than Sarah Jane. The Jacksons were dropped from the series, replaced by Rani Chandra, and her parents Gita and Haresh. Unlike the Jacksons, however — who were almost always a significant part of the narrative — the Chandras were much de-emphasised, and often used as mere comic relief. For instance, it took Haresh two series to amass as many appearances as Alan had enjoyed in a single series. Also, the Chandras were often in just one of the two episodes of a story — as in Death of the Doctor — whereas Alan was typically in both parts. Moreover, the Chandras were all but unused in series 4, appearing together in just one serial. Clyde's parents were featured in one story, but it was a story which hardly utilised Sarah Jane. For the most part, parental involvement dropped significantly after Alan Jackson accepted a job in Washington DC early in series 2, and was little more than incidental after the series 3 premiere.
Over time, even Sarah Jane's new, maternal role was scaled back. Luke Smith's presence began to be scaled back in series 3, such that he was largely absent from several episodes. By series 4, he was said to be in university a year earlier than the two other kids and was thus reduced to a recurring guest star. Practically speaking, the show's format for the last two series featured Sarah Jane, Clyde, Rani and Mr Smith as the major characters, with everyone else reduced to supporting roles.
Common character "beats" that reverberated during the time that Rani was on the show included: the greater involvement of the Doctor in Sarah Jane's life; Haresh's role as the headmaster of the kids' school; the contentious relationship between Sarah Jane's two computers, Mr Smith and K9; Luke's continued communication with an off-screen Maria; the recurring threat of the Trickster; and a certain level of subtle romantic tension between Clyde and Rani.
The development of SJA never attracted the same level of minute coverage of its parent programme. Whereas the production of individual Doctor Who stories was often known in great detail, behind-the-scenes information about SJA was considerably harder to come by.
The project appeared to have started in 2006, slightly prior to the broadcast of School Reunion. At that time, the CBBC expressed an interest in producing a Doctor Who spin-off. Their initial idea was "a drama based on the idea of a young Doctor Who", but Russell T. Davies vetoed this. "Somehow, the idea of a fourteen-year-old Doctor, on Gallifrey inventing sonic screwdrivers, takes away from the mystery and intrigue of who he is and where he came from," said Davies. He suggested instead a series based on the Doctor's former companion Sarah Jane Smith. Reports of a spin-off series first emerged around the time of School Reunion original airing, with the series having the working title of Sarah Jane Investigates. Indeed, Sladen herself was still calling the programme Sarah Jane Investigates as late as an October 2006 BBC interview.
That said, some production milestones were known:
- SJA was invited to submit a sketch for Comic Relief's Red Nose Day appeal in 2009. This made SJA the first Doctor Who spin-off to spawn a mini-episode. From Raxacoricofallapatorius with Love had a viewership of over 9 million, making its audience about 9 times greater than the best audience in SJA history, and about 15 times greater than the average SJA audience.
- In a speech to BAFTA members in March 2009, Davies revealed that production of Series 3 had nearly been cancelled on three occasions due to budget cuts to children's programming at the BBC.
- The SJA broadcast schedule dramatically altered in series 3. Previously aired at the rate of one episode a week, the show switched to a one serial a week rate. This chopped the series broadcast duration in half.
- Series 3 also saw a change in the episodic format, with the pre-titles sequence being shortened because of the addition of an opening narration by Clyde Langer that showed brief clips from the then-current series. This sequence was reused for the 4th and 5th series, with adjustments to the narration to reflect changes in the cast of characters in Series 5.
- The third series received a major ratings boost with a guest appearance by David Tennant as the Doctor, and maintained its momentum throughout the season, consistently scoring higher-than-average viewership for the time period and also scoring high Appreciation Index numbers. The same thing occurred in series 4 following Matt Smith's episodes.
- According to DWM 412, the fourth season was in pre-production from August 2009. On 4 March 2010, the BBC officially announced that production had been commissioned, with filming expected to begin by the end of March.
- Production of the series underwent a scheduling change in 2010, with Series 4 and the first half of Series 5 produced in one production block during the spring-summer of 2010, and filming of the rest of Series 5 planned to follow at a later date. (DWM 425) Ultimately, however, only the three stories of Series 5 filmed in 2010 were completed, as Sladen's death prevented the remainder from being produced.
- On 24 June 2010, BBC News reported that production of Doctor Who and The Sarah Jane Adventures was to relocate to the currently-under-construction BBC Wales "drama village" in Cardiff in 2012, a strong indication that further seasons beyond series 5 were anticipated. However, the sudden death of Elisabeth Sladen permanently suspended production of the show.
The original executive producers for The Sarah Jane Adventures were Russell T Davies and Julie Gardner. Susie Liggat produced Invasion of the Bane, but Matthew Bouch took over for Liggat for series 1 "proper". Phil Collinson held the title of "Series Producer" during the first year. Gareth Roberts — a sort of "uncredited producer" — said of the initial series,
We're all determined that this will be a big, full-blooded drama; that nobody should ever think of it as 'just' a children's programme.
Bouch remained a producer through series 2. For the following year, Nikki Wilson replaced him, and Piers Wenger, Julie Gardner's replacement as Head of Drama at BBC Wales, joined Gardner and Davies as executive producers.
By the fourth series, however, both Gardner and Wenger were no longer credited on the show. RTD was the only exec who remained of the initial main production team. Brian Minchin had become the producer and Nikki Wilson was now RTD's producing partner. She was also the only executive producer actually resident in Wales since RTD was living in Los Angeles during the production of the last two series of SJA, executive producing Torchwood: Miracle Day.
Other important production figures included Phil Ford, who was credited as "co-producer" after series 1, and Debbi Slater, who served in a variety of key production positions over the five series, including those of associate producer and production manager.
The writing staff was fairly stable throughout the programme's run. The job of the head writer was effectively shared between Phil Ford, Gareth Roberts and Russell T Davies for most of the five years — though none of these men actually got a credit as "head writer". Davies did intend to write more stories for the show but on different occasions was forced to pull out being busy with writing Torchwood and Doctor Who, this meant he only ever was credited for writing two stories. Joseph Lidster, Clayton Hickman and Rupert Laight were also frequent contributors.
Production design was handled in the first year by Ed Thomas, alongside Tim Dickel for the series proper, though these duties were eventually given to others in the Doctor Who art department — chiefly Arwel Wyn Jones, who formally succeeded Thomas, and eventually to Keith Dunne. Likewise, the initial casting director was Andy Pryor, but he, too, allowed primary casting responsibilities to eventually fall to his Doctor Who junior, Andy Brierley.
Though the theme music was by Murray Gold, most of the incidental music was actually by Sam and Dan Watts, composers not previously connected with the DWU. Similarly, the cinematography was initially handled by Doctor Who regular, Rory Taylor, but the most prolific director of photography eventually came to be Mark Waters.
- Main article: List of The Sarah Jane Adventures television stories
Ordered in terms of most number of appearances, the main cast consisted of
- Sarah Jane Smith - Elisabeth Sladen
- Clyde Langer - Daniel Anthony
- Mr Smith - Alexander Armstrong
- Luke Smith - Tommy Knight (series 1-3; recurring 4-5)
- Rani Chandra - Anjli Mohindra (series 2-5)
- Maria Jackson - Yasmin Paige (series 1; recurring 2)
- K9 Mark IV - John Leeson (series 3; recurring 1 and 4)
- Sky Smith - Sinead Michael (series 5)
- Haresh Chandra - Ace Bhatti (series 2-5)
- Gita Chandra - Mina Anwar (series 2-5)
- Alan Jackson - Joseph Millson (series 1-2)
- Chrissie Jackson - Juliet Cowan (series 1-2)
Casting decisions were not routinely discussed in the press with anything like the ferocity that Doctor Who casting announcements were. As a result, many cast changes were often the subject of fan speculation more than fact.
During the life of SJA, three kids were edged out of the production, but no official statements were issued by the British Broadcasting Corporation about any of these cast changes.
Kelsey Hooper was apparently the original "third kid" in Invasion of the Bane, but she was quietly replaced in series 1 "proper" by Clyde Langer. No reason was ever given by the BBC for this cast change. However, it is possible to believe that Kelsey was never actually intended as a permanent cast member since Invasion actually wrote her out as unable to handle the "Sarah Jane Smith lifestyle" in its final scenes.
Maria Jackson was the next kid to leave. Though she appeared on much of the series 2 publicity material, and appeared or was heard in three of that year's stories (being referred to in two others), she ceased to be a regular after the first story of the second season. Though rumours have swirled for years about why this character — and, by necessity, her parents — were written out, the BBC has never offered up an explanation for the actor's departure. However, actress Yasmin Paige left the role during her GCSE year and decided she would concentrate on her studies, though it is not clear if she chose to dedicate herself to her scholarly life on a permanent basis and not return to the series.
Finally, Luke Smith was absent for some episodes of series 3 and most of the rest of the programme's run - he only appears in the series 4 opener and finale - though he was still touted as a main cast member in official BBC press packs through the end of the series. Actor Tommy Knight was also clearly part of what was essentially the last thing the BBC filmed about the series, the April 2011 Liz Sladen tribute, My Sarah Jane. This indicated, though perhaps didn't absolutely confirm, that Luke's reduced role was amenable to both the BBC and Knight himself.
Another casting issue was never well understood. K9's appearances were sporadic throughout the five year run of SJA. Since K9 was owned by writer Bob Baker, its appearances had to be specifically negotiated with the writer. Just as School Reunion had raised Sarah Jane's profile, it had also ignited interest in having a K9 spin-off. Baker may have withheld rights for K9's use in SJA so as not to compromise then-ongoing negotiations for a K9 series. Why the dog was so heavily used in series 3, but otherwise little more than a featured cameo in the other series, was never the subject of an official, public announcement.
SJA debuted on BBC One with a 60-minute special on 1 January 2007. A full series of ten 30-minute episodes followed later in the year. The second series had twelve 30-minute episodes and aired in the autumn of 2008, followed by a third in late 2009. A mini-episode for charity also aired in early 2009. Meanwhile, series four went into production in March 2010. At the same time, what was expected to be the first half of the fifth series was produced as part of the Series 4 recording block, with the second half of the series initially planned for production in early 2011.
However, because Elisabeth Sladen died on 19 April 2011,  series 5 was truncated to just those three serials that had been completed in 2010. The series, therefore, ended because Sladen died, and no parties to the production of the series wished to continue without her.
Series 1 aired on the Sci-Fi Channel in the US and BBC Kids in Canada in 2007. In January 2010, Series 2 began airing on BBC Kids. No US broadcast of anything past series 1 ever occurred, and Canada never saw any episode past the second series. Invasion of the Bane was broadcast in Australia on ABC1. Nevertheless, in both Australia and New Zealand, the show started airing in January 2010 on Nickelodeon, though only Series 1-4 were broadcast. It also aired in Brazil on TV Cultura in 2012.
- Merchandising specifics are given on individual series pages, such as series 1 (SJA).
The programme attracted some manufacturing interest. Aside from the obvious retail of the episodes themselves, SJA-themed product ranges included:
- an action figure line coincident with series 1
- novelisations of selected SJA episodes through series 3
- a range of original-to-audio stories
- Lis Sladen talks to BBC Norfolk in October 2006
- Doctor Who News Page - Series 4 Confirmed, accessed 18 January 2010.
- Work starts on BBC Wales drama village in Cardiff Bay, BBC News, 24 June 2010.
- Digital Spy
- BBC Press Releases - Russell T Davies creates new series for CBBC, starring Doctor Who's Sarah Jane Smith (accessed 11th February 2009)
- Doctor Who News Page - Series 4 Confirmed, accessed 18 January 2010.