The chief suspects in the murder of an author are the numerous colleagues whom he continuously plagiarized.
Unfortunately the movie Perry Mason: The Case of the Poisoned Pen is not yet available on Disney Plus.
| Directing | Christian I. Nyby II | Director |
| Writing | Erle Stanley Gardner | Novel |
| Crew | Hal Harrison | Post Production Supervisor |
| Sound | Dick DeBenedictis | Music |
| Sound | Fred Steiner | Original Music Composer |
| Editing | Carter DeHaven | Editor |
| Art | Paul Staheli | Art Direction |
| Camera | Daniel McKinny | Director of Photography |
| Production | David Solomon | Co-Producer |
| Production | Peter Katz | Producer |
| Production | Joel Steiger | Supervising Producer |
| Writing | George Eckstein | Writer |
| Production | Dean Hargrove | Executive Producer |
| Production | Fred Silverman | Executive Producer |
| Production | Billy Ray Smith | Unit Production Manager |
| Directing | Gary Grillo | First Assistant Director |
| Directing | Gail Joyce Fortmuller | Second Assistant Director |
| Production | Reuben Cannon | Casting |
| Production | Carol Dudley | Casting |
| Costume & Make-Up | Ronn Rynhart | Costume Designer |
| Costume & Make-Up | Kelly Andrew King | Costumer |
| Costume & Make-Up | Sharon T. Brunn | Costumer |
| Costume & Make-Up | Dee Sandella | Makeup Artist |
| Costume & Make-Up | Patti Dallas | Makeup Artist |
| Costume & Make-Up | Dionne Smith | Makeup Artist |
| Costume & Make-Up | Brenda Moen | Hairstylist |
| Costume & Make-Up | Rosanne Bigelow | Hairstylist |
| Sound | James Emerson | Production Sound Mixer |
| Lighting | Bradford Lipson | Gaffer |
| Camera | Jerry Jencks | Key Grip |
| Camera | Vincent Baldino | Camera Operator |
| Camera | Douglas O'Kane | First Assistant Camera |
| Production | Debbie Nodella | Production Accountant |
| Production | Andrea Nachman | Production Coordinator |
| Art | Charlie Helms | Set Decoration |
| Art | Susan MacDonald-Petersen | Property Master |
| Directing | Jeff Glasser | Script Supervisor |
| Art | Randy Holland | Construction Coordinator |
| Crew | Gary Jensen | Stunt Coordinator |
| Crew | Gil Talamantes | Transportation Coordinator |
| Production | Karen Beard | Location Manager |
| Production | Donna Colabella | Production Executive |
| Production | Robert Benevides | Production Consultant |
| Crew | Dennis Smith | Legal Services |
| Art | Wayne Fitzgerald | Main Title Designer |
| Editing | Leslie Sackheim | Assistant Editor |
| Production | David Rosenberg | Post Production Coordinator |
| Sound | C.R. Cassey | Music Supervisor |
| Sound | Eileen Horta | Supervising Sound Editor |
| Sound | Bill Nicholson | Sound Re-Recording Mixer |
| Sound | Andy MacDonald | Sound Re-Recording Mixer |
| Sound | Peter Reale | Sound Re-Recording Mixer |
| Sound | Ted Roberts | Music Editor |
| Production | Mike Moder | Executive In Charge Of Production |
