Lost in Character: Kathleen Turner usually feels the role she's playing intensely. In this movie she had terrible nightmares about her dead grandmother calling her on the phone, similar to what Peggy Sue feels in the phone scene.
To 21st-century eyes, the 1986 scenes can seem as weird and gaudy as the 1960 scenes.
Peggy Sue warns her little sister not to eat the red M&M's or she'll get sick. The movie was released during the decade-long period when red M&M's were discontinued due to a health scare involving red dye. (Red M&M's didn't actually use the dye in question.) For the audience of 1986, it was the presence of red M&M's which was dated, but now it's the concern over red M&M's which seems dated.
"For some reason everything else gets tiny, but portable radios get enormous." Of course, she's referring to boomboxes, which are now seen as a fad of The '80s.
Debra Winger was offered the role of Peggy Sue and was actually cast but a back injury from a bicycle accident forced her to withdraw from the film.
When Winger was attached to star, she asked Penny Marshall to direct the film. Marshall met with Tom Hanks and Sean Penn for the male lead, but was fired three weeks into pre-production by the producers, who felt that the film had gotten too big for a first-time director.
Dennis Quaid turned down the role of Charlie Bodell in order to appear in The Big Easy. Steve Guttenberg was also considered.
In the original script, Rosalie, the woman in the wheelchair at Peggy Sue's high school reunion, was a gymnast who was crippled in an accident. In the original script, Peggy Sue tried to take advantage of her knowledge of the future. She invented pantyhose, encouraged people to invest in Xerox, and tried to prevent Rosalie from hurting herself.