Trivia

When Doc Brown first sends Einstein "one minute" into the future, the time elapsed between when the DeLorean disappears and reappears is actually 1 minute 21 seconds, just as the reappearance occurred at 1:21am, and the flux capacitor required 1.21 jigowatts of electricity.

The license plate on a car outside the band audition (which says "FOR MARY") is a tribute to Mary T. Radford, personal assistant to second unit director Frank Marshall.

Another deleted scene shows Marty peeking in on a class in 1955 and seeing his mother cheating on a test.

Wendie Jo Sperber, who played Linda McFly, was in fact three years older than Lea Thompson who played her mother, and six years older than Crispin Glover who played her father.

The Twin Pines Mall is, in fact, the Puente Hills Mall in City of Industry, California. Today, JCPenney is no longer an anchor there.

The school that served as Hill Valley High was Whittier High School in Whittier, California just outside of Los Angeles. It's Richard Nixon's alma mater. Also just beyond the school is where Strickland's home is, as seen later in Back to the Future Part II (1989). The back side of the school can be seen as Marty jogs up to the porch.

The DeLorean was deliberately selected for its general appearance and gull wing doors, in order to make it plausible that people in 1955 would presume it to be an alien spacecraft.

The script never called for Marty to repeatedly bang his head on the gull-wing door of the DeLorean; this was improvised during filming as the door mechanism became faulty.

The time machine has been through several variations. In the first draft of the screenplay the time machine was a laser device that was housed in a room. At the end of the first draft the device was attached to a refrigerator and taken to an atomic bomb test. Robert Zemeckis said in an interview that the idea was scrapped because he and Steven Spielberg did not want children to start climbing into refrigerators and getting trapped inside. (See also Indiana Jones and the Kingdom of the Crystal Skull (2008).) The Nevada desert bomb test was left out in order to reduce the budget. In the third draft of the film the time machine was a DeLorean, but in order to send Marty back to the future the vehicle had to drive the DeLorean into an atomic bomb test.

The film was the top grossing release of 1985.

The picture of Mayor Red Thomas on the election car in 1955 is set decorator Hal Gausman.

Michael J. Fox is only ten days younger than Lea Thompson who plays his mother, and is almost three years older than his on-screen dad, Crispin Glover.

A persistent myth is that Michael J. Fox had to learn to skateboard for the film. In fact, he was a reasonably skilled skateboarder, having ridden throughout high school. However, Per Welinder acted as a skateboarding double for the complex scenes, and Tony Hawk (who had originally been cast as a double when Eric Stoltz was playing Marty, but was too tall to double for Fox) helped choreograph and coordinate the skateboarding action. Bob Gale found Welinder and Hawk practicing on Venice Beach.

Musician Mark Campbell did all of Michael J. Fox's singing. He's credited as "Marty McFly".

Michael J. Fox was allowed by the producer of "Family Ties" (1982) to film this movie on the condition that he kept his full schedule on the TV show - meaning no write-outs or missing episodes - and filmed most of the movie at night. He was not allowed to go on Back to the Future (1985) promotional tours.

Michael J. Fox had always been the first choice for Marty, but he was unavailable due to scheduling conflicts with his work on "Family Ties" (1982). As "Family Ties" co-star Meredith Baxter was pregnant at the time, Fox was carrying a lot more of the show than usual. The show's producer Gary David Goldberg simply couldn't afford to let Fox go. Zemeckis and Gale then cast Eric Stoltz as Marty based on his performance in Mask (1985). After four weeks of filming Robert Zemeckis and Bob Gale felt that Stoltz wasn't right for the part and Stoltz agreed. By this stage, Baxter was back fully on the show and Goldberg agreed to let Fox go off to make the film. Fox worked out a schedule to fulfill his commitment to both projects. Every day during production, he drove straight to the movie set after taping of the show was finished every day and averaged about five hours of sleep. The bulk of the production was filmed from 6pm to 6am, with the daylight scenes filmed on weekends. Reshooting Stoltz's scenes added $3 million dollars to the budget.