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.
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).
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.
There was some early grumbling about Karen Lynn Gorney when filming began. Certain crew members felt she was too old for the part, and that her dancing wasn't up to par (she had sustained serious injuries in a motorcycle accident a few years earlier).