The film was written, directed, and starred in by Jerry Lewis, making it one of the most personally invested projects of his career.

Lewis plays two completely contrasting characters: the timid, socially awkward Professor Julius Kelp and the smug, self-satisfied ladies’ man Buddy Love. The premise draws from the tradition of Strange Case of Dr. Jekyll and Mr. Hyde, filtered through Lewis’s comedic sensibility.

Many critics regard it as the best film Jerry Lewis ever made.

In 2004, the movie was selected for preservation in the United States National Film Registry in recognition of its cultural and historical significance.

The entire production wrapped in just over two months, shooting from October through December of 1962.

The bulk of the film was shot on the campus of Arizona State University in Tempe, Arizona. Viewers paying close attention can spot Arizona State logos on clothing worn by students throughout the background.

The film earned approximately $19 million worldwide, a substantial return for a comedy released in 1963.

Buddy Love remains one of the most recognizable alter egos in the history of comedy cinema. For years, audiences assumed the character was a satirical portrait of Dean Martin, Lewis’s former partner. Lewis consistently denied it. Some viewers found Buddy Love’s mannerisms more reminiscent of Frank Sinatra than of Martin.

Although the film is not a musical, Buddy Love performs several songs throughout. He sings standards including “That Old Black Magic” and “I’m in the Mood for Love.” An original song, “We’ve Got a World That Swings,” was composed specifically for the picture.

RC Cola products appear throughout the film because Lewis was under an endorsement arrangement with the brand at the time. Bottles, vending machines, and delivery trucks all make appearances across various scenes.

Lewis later revealed that Buddy Love generated more fan mail than the gentle Professor Kelp, which genuinely surprised him. He had designed Buddy Love to be off-putting and obnoxious, not someone audiences would find appealing.

The scene in which Kelp dances awkwardly by himself is credited as an influence on a similar moment in Back to the Future, where George McFly finds himself in a comparable situation decades later.

The film landed at number 99 on the American Film Institute’s ranking of the one hundred funniest American movies ever made.

Its success eventually inspired a 1996 remake starring Eddie Murphy, though that version took the basic concept in a substantially different direction.

The film later spawned an animated sequel in 2008 and a stage musical that Lewis personally directed.

In France, the film was received with considerable critical enthusiasm, with influential writers placing it among the best films of 1963. That reception played a meaningful role in establishing Lewis’s reputation as a serious filmmaker in the eyes of European audiences.