Continuity mistake: In one scene, Elvis Presley's prison uniform displays the number 6239, yet in another it becomes 6240.
Visible crew/equipment: During the "How Long Has This Been Going On" number, Hepburn dances by a mirror - reflected in it are the camera crew, desperately trying to get out of the image.
Continuity mistake: When Katharine Hepburn carries the white carnations out of the elevator (which have just been given to her by Gig Young), they turn pink when she steps off the elevator and walks outside.
Other mistake: When Cary Grant came to visit Deborah Kerr, he laid his coat and hat in the chair. Later he remembered he had a gift from his grandmother for her. He did not have it when he came in. Someone had to put it under his coat.
Continuity mistake: When Fred Astaire and Cyd Charisse are dancing among the parallel bars, her skirt changes to cullottes then back again to an ordinary skirt.
Continuity mistake: The Sergeant (played by Karl Malden) is on leave with his family when the car needs water. His daughter (played by Natalie Wood) gets out and refills the water. During the conversation, Malden is bare headed, then immediately after he has a hat on.