William Christopher's movie debut.
Jack Lemmon originally had two other actors proposed to star with him, Frank Sinatra and Jackie Gleason, but he insisted that he do the picture with Walter Matthau.
Jack Lemmon's wheelchair ballet "You'd Be So Nice to Come Home To", lasts 3-1/4 minutes and was completed in one take.
Billy Wilder came up with the idea for this film when he saw a player run into a cameraman on the sidelines while watching a football game.
Average Shot Length (ASL) = 17 seconds
For the scene in which he motors through the city searching for Ron Rich (aka "Boom Boom"), Jack Lemmon also served as a driver, cinematographer and gaffer.
Marked the first pairing of Jack Lemmon and Walter Matthau, who subsequently worked together on 11 additional films (including Kotch, in which Lemmon directed Matthau).
Production was halted for weeks after Walter Matthau had a heart attack. He had slimmed from 190 to 160 pounds by the time filming was completed, and had to wear a heavy black coat to conceal the weight loss.
The game at the opening of the film when Harry gets hurt was played Oct. 31,1965 at Cleveland . The final score was Vikings 27, Browns 17.
This is the first film on which Billy Wilder and Walter Matthau worked together, though Matthau was Wilder's first choice for the part in The Seven Year Itch that was eventually played by Tom Ewell.
This was director Billy Wilder's second film in a row in which one of his lead actors suffered a heart attack. In preceding film, 1964's Kiss Me, Stupid, Peter Sellers' health problem forced Wilder to replace him with Ray Walston. In Fortune Cookie, Walter Matthau suffered attack midway through production but shooting was postponed until he recovered; his drastic weight loss from scene to scene is noticeable.
The Fortune Cookie was the first on-screen collaboration between Walter Matthau and Jack Lemmon.