Bill Murray as Peter Venkman

Dan Aykroyd as Ray Stantz

Sigourney Weaver as Dana Barrett

Harold Ramis as Egon Spengler

Rick Moranis as Louis Tully

Annie Potts as Janine Melnitz

William Atherton as Walter Peck

Ernie Hudson as Winston Zeddemore

Slavitza Jovan as Gozer

David Margulies as Mayor

Steven Tash as Male Student

Jennifer Runyon as Female Student

Michael Ensign as Hotel Manager

Alice Drummond as Librarian

Jordan Charney as Dean Yager

Timothy Carhart as Violinist

John Rothman as Library Administrator

Tom McDermott as Archbishop

Roger Grimsby as Roger Grimsby

Larry King as Larry King

Joe Franklin as Joe Franklin

Casey Kasem as Casey Kasem (voice)

John Ring as Fire Commissioner

Norman Matlock as Police Commissioner

Joe Cirillo as Police Captain

Joe Schmieg as Police Seargeant

Reginald VelJohnson as Jail Guard

Rhoda Gemignani as Real Estate Woman

Murray Rubin as Man at Elevator

Larry Dilg as Con Edison Man

Danny Stone as Coachman

Patty Freedman as Woman at Party

Jean Kasem as Tall Woman at Party

Lenny Del Genio as Doorman

Frances E. Nealy as Chambermaid

Sam Moses as Hot Dog Vendor

Christopher Wynkoop as TV Reporter

Winston May as Businessman in Cab

Tommy Hollis as Mayor's Aide

Eda Reiss Merin as Louis's Neighbor

Ric Mancini as Policeman at Apartment

Kathryn Janssen as Mrs. Van Hoffman

Stanley Grover as Reporter

Carol Ann Henry as Reporter

James Hardie as Reporter

Frantz Turner as Reporter

Nancy Kelly as Reporter

Paul Trafas as Ted Fleming

Cheryl Birchenfield as Annette Fleming

Ruth Oliver as Library Ghost

Kymberly Herrin as Dream Ghost

Billy Bryan as Stay Puft Marshmallow Man (uncredited)

Matteo Cafiso as Boy at Hot Dog Stand (uncredited)

Frankie Como as T-Shirt Vendor (uncredited)

Peter Costanza as Man Fleeing Marshmallow Man (uncredited)

John De Bello as Patrolman Matthews (uncredited)

Paddi Edwards as Gozer (voice) (uncredited)

Eldo Ray Estes as Redheaded Man (uncredited)

Brute Force as Hare Krishna acolyte (uncredited)

Debbie Gibson as Birthday Girl in Tavern on the Green (uncredited)

Willow Hale as Student at Columbia University (uncredited)

Jon Hayden as Library Patron (uncredited)

Ron Jeremy as Man Behind Barricade (uncredited)

Joseph Marzano as Man in Taxi (uncredited)

Joe Medjuck as Man at Library (uncredited)

Danny Nero as Reporter (uncredited)

Frank Patton III as City Hall Cop (uncredited)

Harrison Ray as Terror Dog (uncredited)

Ivan Reitman as Zuul / Slimer (voice) (uncredited)

Frank Rivers as Prisoner (uncredited)

Mario Todisco as Prisoner (uncredited)

Bill Walton as Bill Walton (uncredited)

Mark Bryan Wilson as Slimer (uncredited)