Gregson Wagner's first film role was as Lisa in the film Fathers & Sons in 1992. She then had a small role in the movie Buffy the Vampire Slayer. Following that film she starred in several TV movies including Modern Vampires, Hefner: Unauthorized, and The Shaggy Dog. In 1995, she starred with her step-father Robert Wagner in a Hart to Hart TV movie. She starred in the Wes Craven film The Outpost. In 1996, she co-starred with Jon Lovitz and Tia Carrere in the comedy High School High. She played Lou in the 1997 film Two Girls and a Guy. Gregson Wagner had a small role in the 1998 thriller Urban Legend. That same year she guest starred in an episode of Ally McBeal. In 1998, she appeared in Another Day in Paradise with Vincent Kartheiser and Melanie Griffith.