In this Mel Stuart (Willy Wonka & the Chocolate Factory) directed S*x farce, Ian McShane (TV's Deadwood) stars as roguish Charlie Cartwright, a tour guide with a girl in every port, and Suzanne Pleshette (The Birds) is straight-laced American tourist Samantha Perkins, the would-be object of Charlie's affection. Joining in on the fun-filled 18-day London to Rome excursion are Murray Hamilton (Jaws), Mildred Natwick (Barefoot in the Park), Peggy Cass (Auntie Mame), Norman Fell (TV's Three's Company) and Vittorio de Sica (The Shoes of the Fisherman). Based on the story and screenplay by David Shaw, If It's Tuesday, This Must Be Belgium features cameo performances by John Cassavetes (Rosemary's Baby), Ben Gazzara (Anatomy of a Murder), Joan Collins (TV's Dynasty), Anita Ekberg (La Dolce Vita), Senta Berger (Major Dundee) and Robert Vaughn (TV's The Man from U.N.C.L.E.).