John Travolta had worked hard on the "You Should Be Dancing" sequence and threatened to quit the film when the studio suggested it should be shot in close-up instead of full-body.
Production had to be briefly halted so that John Travolta could attend the funeral of his girlfriend Diana Hyland. The couple had earlier appeared in The Boy in the Plastic Bubble (1976), their only joint venture. It was Hyland who encouraged Travolta to take the role of Tony Manero.
John Travolta ran two miles a day and danced for three hours daily to get in shape for this film. In the end, he dropped 20 pounds.
Allan Carr designed the ad campaign for the film. It was so successful that producer Robert Stigwood asked him to help him produce his next film, Grease (1978).
When they shot the first bridge scene, director John Badham kept secret from Donna Pescow the fact that when the guys "fell off" the bridge, they actually landed on a platform a few feet below. Badham and the other actors did not tell her about the platform because they wanted a genuine look of horror and anger on Annette's face when Tony, Double J. and Joey appeared to fall off. Therefore, Donna's reaction to them falling, and her facial expressions turning from horror and shock to outright anger, were real, and her next line, "You fuckers!", was not scripted.