 | Robert De Niro als David 'Noodles' Aaronson |
 | James Woods als Maximilian 'Max' Bercovicz |
 | Elizabeth McGovern als Deborah Gelly |
 | Treat Williams als James Conway O'Donnell |
 | Tuesday Weld als Carol |
 | Joe Pesci als Frankie Monaldi |
 | Burt Young als Joe |
 | James Hayden als Patrick 'Patsy' Goldberg |
 | William Forsythe als Philip 'Cockeye' Stein |
 | Larry Rapp als 'Fat' Moe Gelly |
| Amy Ryder als Peggy |
 | Scott Schutzman Tiler als Young Noodles |
 | Rusty Jacobs als Young Max / David Bailey |
 | Jennifer Connelly als Young Deborah |
 | Brian Bloom als Young Patsy |
| Adrian Curran als Young Cockeye |
| Mike Monetti als Young 'Fat' Moe Gelly |
| Noah Moazezi als Dominic |
 | James Russo als Bugsy |
 | Darlanne Fluegel als Eve |
 | Danny Aiello als Police Chief Vincent Aiello |
 | Richard Bright als Chicken Joe |
| Frank Gio als Beefy |
 | Ray Dittrich als Trigger |
 | Mario Brega als Mandy |
| Julie Cohen als Young Peggy |
 | Richard Foronjy als Officer Whitey |
 | Olga Karlatos als Woman in the Puppet Theatre |
 | Clem Caserta als Al Capuano |
| Frank Sisto als Fred Capuano |
| Jerry Strivelli als Johnny Capuano |
| Mike Gendel als Irving Gold |
| Sandra Solberg als Friend of Young Deborah |
| Margherita Pace als Young Deborah (Double) |
 | Paul Herman als Monkey |
| Bruno Iannone als Thug |
 | Bruno Bilotta als Chinese Theater Spectator (uncredited) |
| Angelo Florio als Willie the Ape |
 | Marcia Jean Kurtz als Max's Mother |
 | Gerard Murphy als Crowning |
| Dutch Miller als Van Linden |
 | Robert Harper als Sharkey |
| Karen Shallo als Mrs. Aiello |
| Frankie Caserta als Bugsy's Gang |
| Joey Marzella als Bugsy's Gang |
| Marvin Scott als Interviewer |
| Ann Neville als Girl in Coffin |
 | Joey Faye als Adorable Old Man |
| Linda Ipanema als Nurse Thompson |
 | Tandy Cronyn als Reporter 1 |
| Richard Zobel als Reporter 2 |
| Baxter Harris als Reporter 3 |
 | Arnon Milchan als Chauffeur |
| Marty Licata als Cemetery Caretaker |
 | Estelle Harris als Peggy's Mother |
| Gerritt Debeer als Drunk |
| Alexander Godfrey als Newstand Man |
| Cliff Cudney als Mounted Policeman |
| Paul Farentino als 2nd Mounted Policeman |
| Bruce Bahrenburg als Sgt. P. Halloran |
| Mort Freeman als Street Singer |
| Massimo Liti als Young Macrò |
| Jay Zeely als Foreman |
 | Salvatore Billa als One of Beefy's Thugs (uncredited) |
| Greg Anthony als Bar Room Patron (uncredited) |
 | Scott Coffey als Bugsy's Gang (uncredited) |
 | Marco Stefanelli als Bugsy's Gang (uncredited) |
| Matteo Cafiso als Boy in Park (uncredited) |
| Nunzio Giuliani als Speakeasy Drum Player (uncredited) |
| Nelson Camp als Newspaper Salesman (uncredited) |
| Dario Iori als Speakeasy Banjo Player (uncredited) |
| Ole Jorgensen als Speakeasy Percussionist (uncredited) |
| Francesca Leone als David Bailey's Girlfriend (uncredited) |
| Chuck Low als Deborah Gelly's Father (uncredited) |
| Ron Nummi als Waiter (uncredited) |
 | Ryan Paris als Speakeasy Patron (uncredited) |
| Nicola Roberto als Speakeasy Trumpet Player (uncredited) |
| Gianni Sanjust als Speakeasy Clarinet Player (uncredited) |
| Alex Serra als Speakeasy Vocalist (uncredited) |
| Susan Spafford als Nurse (uncredited) |
| Mark Frazer als Pimp (uncredited) |
 | Maria Pia Monicelli als Prostitute (uncredited) |
 | Claudio Mancini als Syndacalist (uncredited) |
 | Rossana Canghiari als Speakeasy Patron (uncredited) |
| Sergio Leone | Director |
| Gabriella Pescucci | Costume Design |
| Gabe Videla | Special Effects |
| Danilo Bollettini | Special Effects |
| Giovanni Corridori | Special Effects |
| Ennio Morricone | Original Music Composer |
| Claudio Mancini | Executive Producer |
| Joy Todd | Casting |
| Carlo Tafani | Camera Operator |
| Romano Mancini | Lighting Technician |
| Arnon Milchan | Producer |
| Cis Corman | Casting |
| Stuart Kaminsky | Additional Dialogue |
| Leonardo Benvenuti | Screenplay |
| Piero De Bernardi | Screenplay |
| Enrico Medioli | Screenplay |
| Franco Arcalli | Screenplay |
| Franco Ferrini | Screenplay |
| Sergio Leone | Screenplay |
| Harry Grey | Novel |
| Vincenzo Cardella | Hairstylist |
| Maria Teresa Corridoni | Hairstylist |
| Renata Magnanti | Hairstylist |
| Randy Coronato | Hairstylist |
| Randy Coronato | Makeup Artist |
| Nilo Jacoponi | Makeup Artist |
| Manlio Rocchetti | Makeup Artist |
| Gino Zamprioli | Makeup Artist |
| Fred C. Caruso | Executive In Charge Of Production |
| Mario Cotone | Production Supervisor |
| Walter Massi | Unit Manager |
| Ginette Hardy | Production Manager |
| Nino Baragli | Editor |
| Tonino Delli Colli | Director of Photography |
| Giovanni Natalucci | Production Design |
| Carlo Simi | Art Direction |
| James T. Singelis | Art Direction |
| Bruno Cesari | Set Decoration |
| Osvaldo Desideri | Set Decoration |
| Gretchen Rau | Set Decoration |
| Henry R. Dwork | Makeup Artist |
| Giancarlo De Leonardis | Hairstylist |
| Dennis T. Benatar | Assistant Director |
| Philippe Landoulsi | Assistant Director |
| Luca Morsella | Assistant Director |
| Fabrizio Sergenti Castellani | First Assistant Director |
| Amy Wells | Assistant Director |
| Ronald Fauteux | Props |
| Gianni Fiumi | Property Master |
| Alain Giguère | Painter |
| Nello Giorgetti | Swing |
| Steven Kirshoff | Props |
| Walter Klymkiw | Head Carpenter |
| Joey Litto | Construction Coordinator |
| Tullio Lullo | Construction Coordinator |
| Roberto Magagnini | Props |
| Claude Simard | Head Carpenter |
| Martin Cats | Props |
| Dan Mahoney | Construction Grip |
| Kathy Wolf | Painter |
| Fabio Ancillai | Boom Operator |
| Italo Cameracanna | Foley Artist |
| Italo Cameracanna | Sound Effects Editor |
| Fernando Caso | Sound Effects Editor |
| Bruno Charier | Boom Operator |
| Enzo Diliberto | Foley Artist |
| Alvaro Gramigna | Foley Artist |
| Fabio Palmisano | ADR Editor |
| Daniele Quadroli | Sound Effects Editor |
| Massimo Rinchiusi | ADR Editor |
| Jean-Pierre Ruh | Sound Engineer |
| Jacques Thomas-Gérard | Sound Re-Recording Mixer |
| Luigi Porto | Sound Assistant |
| Elliot Tyson | Sound Re-Recording Mixer |
| Louis Craig | Special Effects Assistant |
| André Laperrière | Special Effects Technician |
| Steve Lombardi | Special Effects Coordinator |
| Olivier Zenenski | Special Effects Assistant |
| Brian Campbell | Special Effects |
| Benito Stefanelli | Stunt Coordinator |
| Steve Baker | Key Grip |
| Sandro Battaglia | Assistant Camera |
| Rodney Bauer | Grip |
| Elio Bosi | Grip |
| Marco Contaldo | Electrician |
| Augusto Diamanti | Key Grip |
| Amato Gabotti | Grip |
| Normand Guy | Key Grip |
| Walter Klymkiw | Gaffer |
| Romano Mancini | Gaffer |
| John Newby | Gaffer |
| Crescenzo G.P. Notarile | Assistant Camera |
| Angelo Novi | Still Photographer |
| Antonio Scaramuzza | Assistant Camera |
| Kurt Thompson | Dolly Grip |
| Carlo Vinciguerra | Gaffer |
| Eraldo Barbona | Grip |
| Edward Cohen | Electrician |
| Jean Courteau | Electrician |
| Sylvie Bourque | Extras Casting |
| Flo Gallant | Extras Casting |
| Helen P. Butler | Costumer |
| Marina Frassine | Assistant Costume Designer |
| Dougie Hawkes | Costumer |
| Raffaella Leone | Assistant Costume Designer |
| Alessandro Baragli | Assistant Editor |
| Patrizia Ceresani | Assistant Editor |
| Ornella Chistolini | Assistant Editor |
| Lizi Gelber | Assistant Editor |
| Zach Staenberg | Additional Editor |
| Elvira Tonini | First Assistant Editor |
| Giorgio Venturoli | Assistant Editor |
| J. Kathleen Gibson | First Assistant Editor |
| Howard Heard | Assistant Editor |
| Pierre Laberge | Location Manager |
| Robert Rothbard | Location Manager |
| Attilio Viti | Location Manager |
| Edda Dell'Orso | Vocals |
| Ennio Morricone | Music Director |
| Gheorghe Zamfir | Musician |
| Pierluigi Pietroniro | Musician |
| James Giblin | Transportation Captain |
| Patrick Hogan | Transportation Captain |
| Bobby Marsh | Driver |
| Francesca Alatri | Production Secretary |
| Bruce Bahrenburg | Unit Publicist |
| Robert Benmussa | Consulting Producer |
| Dominique Bruballa | Accountant |
| Fausto Capozzi | Accountant |
| Maurizio Cusano | Production Assistant |
| Diana Di Michele | Accountant |
| Lucie Drolet | Accountant |
| Gail Kearns | Production Coordinator |
| Antonio Palombi | Production Assistant |
| Sergio Rosa | Accountant |
| Pietro Sassaroli | Production Assistant |
| Jennifer W. Shore | Production Secretary |
| Eric P. Steckler | Production Assistant |
| Reuben Gonzalez | Production Assistant |
| Simona Patitucci | Production Assistant |
| Eugene Rizzo | Unit Publicist |
| Danièle Rohrbach | Production Coordinator |
| Hedy Martinelli | Thanks |
| Chris David | Dolby Consultant |
| Jacques Godbout | Special Effects |
