Throughout filming, RKO executives complained that the film was destined for commercial failure. They asked Howard Hawks to insert more romance and less slapstick and told him to take away Cary Grant's glasses, but he ignored them.
Katharine Hepburn had never done any comedy before, and was coached by Howard Hawks and several veteran vaudevillians he employed solely for that purpose. As a former vaudevillian, Cary Grant was already well versed in comedy.
The scene in which Susan's dress is ripped was inspired by something that happened to Cary Grant. He was at the Roxy Theater one night and his pants zipper was down when it caught on the back of a woman's dress. Grant impulsively followed her. When he told this story to Howard Hawks, Hawks loved it and put it into the film.
Christopher Reeve based his performance as Clark Kent in Superman (1978) and its three sequels on Cary Grant's character David Huxley from this film.
Despite Katharine Hepburn's knack for working with Nissa, the studio wasn't taking any chances. Some scenes involving the leopard, like the drive to Connecticut, were done as process shots, with Nissa matted into the shot separately from the actors. This is evident when Cary Grant observes that "Baby" is "eating the car" - slightly before the leopard begins gnawing. For the scene in which Hepburn drags Baby into the jail house, one can even see the break between the rope Hepburn is holding and the rope attached to the cat.