André Morell was offered the role of Wyler, but could not accept because he had signed to star in the four-part Doctor Who serial, "The Massacre" with William Hartnell, which clashed with the filming dates.
Sheila Steafel was dubbed.
Bernard Cribbins would return to the Doctor Who franchise in 2007, starring as a recurring character, Wilfred Mott, in the fourth season of Doctor Who. Unlike the movie, the TV series is considered canon by the BBC.
Dr. Who and the Daleks co-stars Roy Castle and Jennie Linden were both unavailable when the film was green-lit, hence Ian and Barbara become Tom and Louise.
Keith Marsh, playing Conway, only appears in the film after Wells actor Roger Avon had to leave the production and his character therefore had to be replaced.
A remake of the 1964 Doctor Who serial "The Dalek Invasion of Earth".
By sheer coincidence the "rels counter" 'clockface' from the Dalek control room can be glimpsed in the parent TV series, in both the third edition of 1966's "The War Machines" and the fourth of "The Underwater Menace" the following year.
Despite bearing the credit "An AARU Production", this film (and its forerunner Dr. Who and the Daleks) was made entirely by Amicus. AARU received the sole production credit as part of a co-finance deal with Amicus, which felt it couldn't afford to make a movie of this scale by itself.
Stuntman Eddie Powell broke his ankle in a fall through an awning. He returned from hospital that afternoon with a cast on his leg and finished the scene. His brother, Joe Powell, who was also doing stunt work on the film, pulled off the Black Dalek's claw during a fight scene when he was playing one of the robomen and gets himself thrown down the bomb hole near the end of the movie. The claw magically reappeared in the next shot.
The 1960s street where the opening robbery takes place is the same one on which Wyler and Susan encounter a Dalek patrol over 180 years later (the unchanged Mitchell Real Estate premises and Harris & Son shop are prominent in both sequences). In reality this was part of the backlot at Shepperton.
The Dalek saucer model resurfaced in Tigon's Thin Air
The film's trailer curiously contained no direct reference to either the Daleks, Doctor Who or the TARDIS.
The original trailer for this film describes Ray Brooks as "The boy with the knack". Brooks starred in The Knack... and How to Get It.
The rebel hideout in 2150 is prominently identified as Embankment station on the London Underground's Bakerloo and Northern Lines. There had actually been a station called Embankment once, but it was renamed in 1914; thus this was a suitable name for a fictional station. However, in 1976, 10 years after the movie was released, reality conformed to fiction when the station, now served by the Bakerloo and Northern Lines among others, was given back its original name of Embankment.
This film was part-financed by the company that makes "Sugar Puffs" cereal, in return for an exclusive merchandising deal. Several posters for "Sugar Puffs" cereal are visible during the movie, an early (for a British movie) example of product placement.
This sequel to Dr. Who and the Daleks was to have been followed by a third film, to be based on the 1965 TV episode "The Chase." This was never made.
Tom's surname originated when Subotsky adapted Terry Nation's original scripts, which feature a character called David Campbell. This is why Ray Brooks' character has no surname.