Corey Haim's first day of shooting was with Peter Weller, and he went up to compliment the older actor on his performance. Weller collared Haim, throwing him up against a wall to warn him not to speak to him after a take, and it took three assistants to separate them. Haim later admitted that he was terrified by the experience, but Weller apparently was method acting, unaware by anybody else.
After meeting each other on the set of this movie, Robert Downey Jr. and Sarah Jessica Parker later dated, until they broke up in 1991.
The scene where Jake (Christopher Collet) (on a motorbike) is being pursued by Sam (Peter Weller) in the SUV, was filmed in Morristown, New Jersey. In an attempt to shake off Sam, Jake gets up on the New Jersey Transit tracks, and is soon overtaken by a commuter train. During the sequence, which involved several takes, veteran stuntman Bill Anagnos (doubling Christopher Collet) was actually struck by the train, and was knocked off the right-of-way, suffering a broken leg. With heavy editing of the previous takes, the accident was not shown, and the film progressed from there. After a long period of painful recuperation, Bill Anagnos eventually returned to stunt work.