Trivia

The character of Henry Orient was inspired by real-life concert pianist Oscar Levant. Nora Johnson, who wrote the novel on which the movie was based (and co-wrote the screenplay with her father, Nunnally Johnson), said that she and a friend had a crush on Levant when they were schoolgirls.

The phone Henry Orient (Peter Sellers) used in his bedroom is called a Ericofon, made by L.M. Ericsson of Sweden. This is one of the very few foreign phones allowed in the U.S. at the time of filming by the then telephone company, Bell Telephone, which held a monopoly on telephone service and telephone equipment in the US. Bell Telephone felt so threatened by the unique European design (and possible mass intrusion into "their" telephone network) that they designed the "Trimline" phone as a countermeasure.

Included among the American Film Institute's 2000 list of the 500 movies nominated for the Top 100 Funniest American Movies.

During the making of this movie, Peter Sellers had problems of his own with a fan stalking him.

Peter Sellers' accent changes from a generic European accent to a New York/Brooklyn accent. His New York accent was an imitation of Stanley Kubrick's voice. Kubrick directed Sellers in Lolita (1962) and Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964).