Al Jolson's appearance singing "Swanee" is his final credited performance in a film, but not his last appearance on screen. In The Jolson Story he appears as himself, unbilled, in one scene, again singing "Swanee".

John Garfield expressed interest in playing George Gershwin.

Oscar Levant had three functions in this film: he provided George Gershwin's piano playing as Robert Alda's double, he portrayed himself on screen and he was heard playing piano on the soundtrack as himself, Oscar Levant, in the commemorative performance of "Rhapsody in Blue" which ends the film.

Director Irving Rapper wanted Tyrone Power to play George Gershwin, but he was serving in the U.S. military during World War II and was therefore unavailable.

Film debut of Robert Alda.

Filmed between July 19 and October 12 of 1943, the movie's release was delayed until the Manhattan premiere at the Hollywood Theatre on June 27, 1945. Nearly three months later, the picture opened nationally on September 22, 1945.

The Catfish Row set seen in the "Porgy and Bess" sequence is an exact duplicate of the original 1935 set for the first Broadway production of the opera.

The characters played respectively by Alexis Smith, Joan Leslie, and Albert Bassermann are fictional. There was no love triangle between Gershwin and the two women, and Gershwin's music teacher did not die the night that "Rhapsody in Blue" premiered. The scene in which Gershwin is fired by the music publisher for playing his own music is also fictional. However, most of the other characters in the film did exist, including Max Dreyfus, and Anne Brown, who played Bess in the original "Porgy and Bess" is still alive ca. early 2009.