Joan Sims complained to the Director Gerald Thomas about Kenneth Williams's behaviour while filming a love scene. Williams broke wind violently during the scene, which took Sims completely by surprise.
Joan Sims wore a body stocking during the dance scene due to her own concerns about her weight.
Tommy Cooper was originally asked to play the role of the Fakir but he was unavailable. Cardew Robinson was then cast in the role.
Princess Margaret visited the set during filming, she was shown a clip which includes the scene in which Sir Sidney Ruff-Diamond writes to Queen Victoria, in which Sir Sidney says "Dear Vicky". Princess Margaret was said to be furious about this joke.
In the dinner scene, the cast was served ham and boiled potatoes.
Lady Ruff Diamond's line, "Oh dear! I seem to have got a little plastered," was an ad lib by Joan Sims which was kept in. Julian Holloway's (Major Shorthouse) reaction to the line was genuine.
Snowdonia in Wales doubled as the Khyber Pass with the rest of filming done at Pinewood Studios. When the film was released, an old soldier who had served in the Khyber Pass area wrote to the film studio, informing them that he recognized the area at once.
The censor had a problem with Bungdit Din's line, "Fakir, off!" A sufficient pause was required between the words "Fakir" and "off".
The Rank Organisation, which had recently taken over as distributor of the Carry On films, was initially reluctant to use the title "Carry On Up The Khyber" because "Khyber Pass" is Cockney rhyming slang for arse/ass. Instead they wanted to change the title to "Carry On Up The Regiment".
There is an in-joke to the Rank Organisation: when someone bangs a gong (the trademark symbol of Rank), the Khasi describes it as "rank stupidity".
To receive an 'A' (PG) cinema certificate some risqué dialogue was removed including Brother Belcher's request for "A tool to dig with" and Bungdit Din mentioning a "travelling fakir". The print remains edited to this day.
When the first Gulf War started, this film was banned from being shown on British television.