Al Pacino
Officer Frank Serpico

John Randolph
Sidney Green

Jack Kehoe
Tom Keough

Biff McGuire
Captain McClain

Barbara Eda-Young
Laurie

Cornelia Sharpe
Leslie Lane

Tony Roberts
Bob Blair

John Medici
Pasquale

Allan Rich
D. A. Tauber

Edward Grover
Lombardo

Albert Henderson
Peluce

Hank Garrett
Malone

Damien Leake
Joey

Joseph Bova
Potts

Gene Gross
Captain Tolkin

Woodie King Jr.
Larry

James Tolkan
Steiger

Ed Crowley
Barto

Bernard Barrow
Palmer

Sal Carollo
Mr. Serpico

Nathan George
Smith

Richard Foronjy
Corsaro

Alan North
Brown

Lewis J. Stadlen
Berman

Ted Beniades
Sarno

M. Emmet Walsh
Gallagher

Charles White
Delaney

F. Murray Abraham
Detective Partner (uncredited)

P.J. Benjamin
Man (uncredited)

Val Bisoglio
Weapons Storage Officer (uncredited)

John Brandon
Police Lieutenant (uncredited)

Sam Coppola
Cop (uncredited)

René Enríquez
Cervantes Teacher (uncredited)

Frank Gio
Police Lieutenant (uncredited)

Trent Gough
Cop (uncredited)

Nick Hardin
Television Cameraman (uncredited)

Judd Hirsch
Cop (uncredited)

Richard Kuss
Detective (uncredited)

Tony Lo Bianco
Cop (uncredited)

George Loros
Det. Glover (uncredited)

Kenneth McMillan
Charlie (uncredited)

Stephen Pearlman
Desk Sergeant (uncredited)

Jay Rasumny
Television Cameraman (uncredited)

Tom Signorelli
Bookmaker (uncredited)

Ben Slack
Detective Sitting At Desk (uncredited)

Jaime Sánchez
Cop (uncredited)

Tracey Walter
Street Urchin (uncredited)

Mary Louise Weller
Sally - Girl at Party (uncredited)

Judd Omen
Doctor