This film was improvised from a 56-page outline. Each scene was shot in sequence, and built upon the previous scene. To aid in this experiment, the film's producers had a video-camera tube attached to the Panavision camera and connected to an Ampex studio videotape machine, allowing the actors and crew to review what they had just filmed.
During the scene in which Peter Sellers wrecks the upstairs bathroom, the band downstairs can be heard playing "It Had Better Be Tonight," which was originally written and used both as a vocal and as an instrumental score in the first "Pink Panther" film.
Associate producer Ken Wales nearly drowned during filming, after stuntman Dick Crockett shoved him into the foam-filled swimming pool as a joke. No-one had told either man that the foam was actually designed for use by firefighters, and absorbed oxygen in order to help put out fires, meaning that Wales couldn't breathe even when he was above the water, and had to be rescued by a couple of stagehands.