Director David Swift was greatly annoyed throughout the filming by the behavior of leading man Glenn Ford , later telling an interviewer that if Ford were his child, "I would spank him".
Glenn Ford and Hope Lange were in a long-standing relationship when this movie was made.
Millie's fortune of $40 million in 1963 would be worth almost $400 million in 2023.
Ulla Jacobsson receives a special "introducing" credit - even though she had been a busy and well-known film actress for a number of years and had been seen in over twenty films, some of which had been very widely seen in the United States.