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.
There were holes (due to rust) under the door of the car used in the film and water leaked inside during the rain scene. There was five inches of water in the car.
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!
Charles Hawtrey's mother would often visit the set wearing a black veil and would not come out of her dressing room.
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.
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 (1967).
The role of the coach driver, Jim Tanner, was originally offered to Jim Dale
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.
When Barbara Windsor did her first line and scene, Gerald Thomas immediately said cut and print as he considered it good enough to go into the film. But Windsor immediately said "I'll f***ing cut it, I didn't want to play it that way!" The whole set fell about laughing.
The monastery scene was filmed on November 7th 1968.
There was a deal with Saxa Salt and there was blatant product placement in the film during one scene with Charles Hawtrey, this was unusual in the UK in the 1960s.
Betty Marsden was terrified of riding the tandem bicycle which was an important part of her scenes during filming.
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.
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 (1968) was the second grossing film that year.
Filming took place during Autumn and leaves had to be stuck back onto the trees and sprayed green in order to recreate Summer.
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.