During the filming, Charles Hawtrey's mother would often visit the set. Whilst enjoying a cigarette, she accidentally dropped lit ash from the cigarette into her handbag. Joan Sims who was the first to spot the incident yelled, "Charlie Charlie, your mother's bag is on fire!". Hawtry poured his cup of tea into the bag, snapped it shut, and carried on.
A song on Morrissey's first album entitled "Late Night Maudlin Street" is named after the school in this film.
The name Allcock was questioned by the 1950s' censors, especially how much the characters constantly say it with such precision on the "cock" part, but they eventually allowed it to pass.
It was no accident that Charles Hawtrey was cast as the music master, as he was a classically-trained pianist and former boy soprano.
Ted Ray was under contract to Associated British (ABC), but wasn't used by them. So they weren't happy when he turned up in another distributor's film, especially one as successful as this one. Due to the possibility of the film not getting a release on the ABC cinema circuit, Ray was quietly dropped from the Carry Ons. He was supposed to be in the next one, Carry on Constable (1960).