Paul Newman was coached in playing the trombone by Billy Byers, while the playing for Newman on the soundtrack was done by Murray McEachern. Sidney Poitier's tenor sax playing was done by Paul Gonsalves. The soundtrack was recorded May 1-3, 1961 at Reeves Sound Studios in New York City.
During the shooting, Paul Newman and his wife Joanne Woodward got tired of French food restaurants and searched backyards, in deep winter, to grill steaks. The neighbors were aghast.
It was during filming of this movie that Joanne Woodward became pregnant with Melissa Newman, who was born the day the film opened in the U.S.
Marlon Brando's Pennebaker Films co-produced, and Paul Newman was cast after Brando lost interest in the film. Marilyn Monroe was also considered for Joanne Woodward's role before she too lost interest.
The Paris bird market, where Gypsy and Ram walk as Gypsy seeks a fix, happens Sunday mornings on the Île de la Cité. As of 2021, authorities are moving to shut it down permanently.