In order to save an assassinated scientist, a submarine and its crew are shrunk to microscopic size and injected into his bloodstream.
| Directing | Richard Fleischer | Director |
| Production | Saul David | Producer |
| Sound | Leonard Rosenman | Original Music Composer |
| Camera | Ernest Laszlo | Director of Photography |
| Editing | William B. Murphy | Editor |
| Art | Dale Hennesy | Art Direction |
| Art | Jack Martin Smith | Art Direction |
| Art | Stuart A. Reiss | Set Decoration |
| Art | Walter M. Scott | Set Decoration |
| Writing | David Duncan | Adaptation |
| Writing | Otto Klement | Story |
| Writing | Jerome Bixby | Story |
| Writing | Harry Kleiner | Screenplay |
| Costume & Make-Up | Margaret Donovan | Hairstylist |
| Costume & Make-Up | Ben Nye | Makeup Artist |
| Production | Eric Stacey | Unit Production Manager |
| Directing | Ad Schaumer | Assistant Director |
| Sound | Bernard Freericks | Sound |
| Sound | David Dockendorf | Sound |
| Crew | L.B. Abbott | Special Effects |
| Crew | Art Cruickshank | Special Effects |
| Crew | Emil Kosa Jr. | Special Effects |
| Production | Harper Goff | Researcher |
| Crew | Fred Zendar | Technical Advisor |
| Crew | Peter Foy | Aerial Coordinator |
| Art | Richard Kuhn | Title Designer |
| Sound | Walter Rossi | Sound Effects |
