Matthew Lawrence as Frank Stein

Ryan Reynolds as Karl O'Reilly

Justin Walker as Lance Kipple

Christine Lakin as Macy

Shelley Duvall as Mrs. Stein

Judge Reinhold as Mr. Stein

Richard Moll as Mr. O'Reilly

Christian Payne as Tuttle

Charles Fleischer as Mr. Stockton

Kenn Michael as Jordy

Bianca Lawson as Darien Stompanato

Nicole Nieth as Andrea Shrelonzky

Bradley Jay Lesley as Arnie

Eric Siegel as Officer Scott

Richard Speight Jr. as Comic Book Salesman