In 1987, Kramer made his acting debut in television film The Gunfighters. He also starred in the 1990 film Quest for the Mighty Sword, replacing previous lead actor Miles O'Keeffe. He played Thor in NBC's television film The Incredible Hulk Returns and a Russian baseball player in the television movie The Comrades of Summer. Among Kramer's more notable roles have been Little John in Robin Hood: Men in Tights, Bear in American Wedding, and Boris, bodyguard to producer Lee Donowitz, in True Romance. He has also appeared in a number of notable television series, including Two and a Half Men, Wizards of Waverly Place, Growing Pains, Cheers, Empty Nest, Blossom, CSI: Crime Scene Investigation, NewsRadio, JAG, Roseanne, Murder, She Wrote, Seinfeld, That '70s Show, Ellen, Monk, Jack and Bobby, Phil of the Future, How I Met Your Mother, The King of Queens and My Name Is Earl. Kramer was also a series regular on the sitcom Bob as Whitey van de Bunt (1993) and the ABC/UPN sitcom The Hughleys as Dave Rogers.