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.
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.