Simon

Alan Arkin

as Simon Mendelssohn

Madeline Kahn

as Dr. Cynthia Mallory

William Finley

as Fichandler

Wallace Shawn

as Eric Van Dongen

Max Wright

as Leon Hundertwasser

Fred Gwynne

as Maj. Gen. Korey

Austin Pendleton

as Dr. Carl Becker

Judy Graubart

as Lisa

Adolph Green

as Commune Leader

Keith Szarabajka

as Josh

Ann Risley

as Pam

David Susskind

as Himself

Dick Cavett

as Himself

Billie Perkins

as Commune Member

Jayant

as Barundi

Pierre Epstein

as Military Aide

Roy Cooper

as General's Aide

Rex Robbins

as Army Doctor

David Warrilow

as Blades

David Gideon

as Security Guard

Hetty Galen

as Simon's Mother (voice)

Remak Ramsay

as TV Newscaster

Hansford Rowe

as Priest Babcock Beastly

Yusef Bulos

as Hemling Grotowsky

Jerry Mayer

as Prof. Jerry Milstein

Sol Frieder

as Rabbi Chaim Glassberg

William Griffis

as Senator

Frank J. Lucas

as Psychologist

George Riddle

as Muttonchop Aide

Tom Kubiak

as Roach Reaction Patient

Al Cerullo

as Helicopter Pilot

Barbara Mongin

as Institute Staff Member

Paula Gibson

as Melody

James Dukas

as Narrator (voice)

Jim Saxon

as Commune Member

Michael Earl

as Commune Member

Jay Lowman

as Commune Member

Steven Nash

as Commune Member

Barbara Bergen

as Commune Member

Joyce Adams

as Commune Member

Bonnie Deroski

as Commune Member

Kathryn Cordes

as Commune Member

Leslie Frances Williams

as Commune Member

Nick Pippin

as Commune Member

Ed Karvoski

as Commune Member

Mary Lou Kleinbach

as Commune Member

Richard Bassett

as Commune Member

Phil Witt

as Commune Member

Isam Culver

as Commune Member

Rickey Murray

as Commune Member

Stephanie Segal

as Commune Member

Max Goff

as Commune Member

Mary Donnet

as Commune Member

Don Stitt

as Commune Member

Nikki Kollins

as Commune Member

Jenny Gault

as Commune Member

Regina Rodwell

as Commune Member

Schorling Schneider

as Commune Member

Tina Austin

as Commune Member

Jeffrey Bacon

as Commune Member

Elizabeth Wingate

as Commune Member

Joan Adams

as Commune Member

Lisa Maurer

as Commune Member

Louise Lasser

as Doris (voice) (uncredited)