Marty McFly, a typical American teenager of the Eighties, is accidentally sent back to 1955 in a plutonium-powered DeLorean "time machine" invented by a slightly mad scientist. During his often hysterical, always amazing trip back in time, Marty must make certain his teenage parents-to-be meet and fall in love - so he can get back to the future.

After a wacky trip to 1955, Marty McFly returns to his own time only to find himself going with his friend Doc Brown to the year 2015 to straighten out a family problem. When they return to 1985 however, they quickly discover that Biff Tannen has turned Hill Valley into a hell hole. Their only chance to restore their original time is to return to 1955 to set things right.

Stranded in 1955, Marty McFly receives written word from his friend, Doctor Emmett Brown, as to where can be found the DeLorean time machine. However, an unfortunate discovery prompts Marty to go to his friend's aid. Using the time machine, Marty travels to the old west where his friend has run afoul of a gang of thugs and has fallen in love with a local schoolteacher. Using the technology from the time, Marty and Emmett devise one last chance to send the two of them back to the future.