A corrupt CIA agent Sands hires hitman El Mariachi to assassinate a Mexican general hired by a drug kingpin attempting a coup d'état of the President of Mexico.
Unfortunately the movie Once Upon a Time in Mexico is not yet available on HBO Max.
| Directing | Robert Rodriguez | Director |
| Writing | Robert Rodriguez | Screenplay |
| Editing | Robert Rodriguez | Editor |
| Sound | Robert Rodriguez | Original Music Composer |
| Crew | Joe Bucaro III | Stunts |
| Crew | Jimmy Ortega | Stunts |
| Production | Carlos Gallardo | Producer |
| Sound | Robert Rodriguez | Sound Effects Editor |
| Production | Sue Jett | Co-Producer |
| Costume & Make-Up | Sandra Migueli | Makeup Artist |
| Production | Jane Nerlinger Evans | Executive In Charge Of Production |
| Directing | Korey Scott Pollard | Second Assistant Director |
| Art | Kara Sutherlin | Standby Painter |
| Costume & Make-Up | Roxie Hodenfield | Hair Department Head |
| Production | Luz María Rojas | Co-Producer |
| Crew | Brian McNulty | Post Production Supervisor |
| Costume & Make-Up | Graciela Mazón | Costume Design |
| Production | Tony Mark | Unit Production Manager |
| Costume & Make-Up | Carmen de la Torre | Makeup Artist |
| Art | Carlos Azucena | Assistant Property Master |
| Sound | James J. Mase | Boom Operator |
| Sound | Ernesto Muñoz | Boom Operator |
| Sound | Sergio Reyes | Sound Re-Recording Mixer |
| Costume & Make-Up | Ermahn Ospina | Makeup Department Head |
| Art | Eva Castro | Set Decoration |
| Directing | Brian Bettwy | First Assistant Director |
| Sound | Dean Beville | Sound Designer |
| Sound | William Jacobs | Sound Designer |
| Art | Patrice Laure | Set Decoration |
| Art | Melo Hinojosa | Art Direction |
| Editing | Val Kuklowsky | Dialogue Editor |
| Production | Elizabeth Avellan | Producer |
| Production | Tony Mark | Co-Producer |
| Production | Robert Rodriguez | Producer |
| Costume & Make-Up | Carmen de la Torre | Hairstylist |
| Production | Mary Vernieu | Casting |
| Art | Robert Rodriguez | Production Design |
| Art | Kevin Berve | Assistant Property Master |
| Crew | Mike Reedy | Special Effects Coordinator |
| Sound | Mike Chock | Sound Effects Editor |
| Sound | Ed Novick | Production Sound Mixer |
| Crew | Sergio Jara | Special Effects Coordinator |
| Art | Caylah Eddleblute | Property Master |
| Art | Alberto Villaseñor | Construction Coordinator |
| Sound | Matthew C. Beville | Foley Editor |
| Sound | John Dunn | Sound Effects Editor |
| Art | Carlos Benassini | Assistant Art Director |
| Sound | Robert Rodriguez | Sound Re-Recording Mixer |
| Sound | Sean Landeros | Sound Recordist |
| Editing | Charles Ewing Smith | Dialogue Editor |
| Art | King Orba | Set Dresser |
| Crew | Troy Robinson | Stunt Coordinator |
| Camera | Robert Rodriguez | Director of Photography |
| Crew | Jeffrey J. Dashnaw | Stunt Coordinator |
