Charles Hawtrey's mother would often visit the set wearing a black veil and would not come out of her dressing room.
Terry Scott was suffering with hemorrhoids during filming.
Trisha Noble was always late for filming, which caused upset on the set. There were concerns that she did not fit in with the rest of the team. Ironically, she actually had the first line on the first day of filming during the girls campsite shower scene.
Dilys Laye was allowed by producer Peter Rogers to keep costumes worn in this film, in particular the green and pink dress worn during the cinema scene.
Betty Marsden said during filming to Dilys Laye that she always wanted to die with a glass of gin in her hand. In Denville Hall, a home for old actors, twenty four hours after arriving in July 1998, this is exactly what happened. Miss Marsden collapsed and died at the home's bar, whilst drinking gin.
Betty Marsden was terrified of riding the tandem bicycle which was an important part of her scenes during filming.
A scene with Trisha Noble and 'Julian Holloway (I)' was cut from the final film. Noble also does not appear in the final sequence, which includes all the other cast members.
During one take Barbara Windsor fell into the the mud in the bra flying scene. Several takes were necessary because the bra apparatus had technical problems, even though it was a fishing rod!
Filmed during a rainy autumn that produced LOADS of mud. This can be seen frequently through the film, including people sinking & slipping. To hide the mud, green paint was used. The leaves (which had by now either dropped or turned brown) were spray-painted.
Filming took place during Autumn and leaves had to be stuck back onto the trees and sprayed green in order to recreate Summer.
In the rave scene, which took a few days to film, the extras who dance are actually locals from the nearby village. It was filmed on 5 and 6 November 1968.
Last ever "Carry On..." film for Dilys Laye.
Premiered in Hull, England, people were literally queuing around the block to see it. It was the highest grossing film in the United Kingdom in 1969. Carry On... Up the Khyber was the second grossing film that year.
The "nudie" film that Sid and Bernie take the girls to see is Nature's Paradise.
The film initially received an 'R' rating in America and was refused a cinema certificate in Ireland.
The monastery scene was filmed on November 7th 1968.
The role of the coach driver, Jim Tanner, was originally offered to Jim Dale
There is an in house joke - in the scene when Doctor Soaper and Miss Haggerd discuss love in the tent, Miss Haggerd refers to her previous job in a hospital. This refers to Carry on Doctor.