| Cast overview, first billed only: | |||
| Charlton Heston | ... | Detective Thorn | |
| Leigh Taylor-Young | ... | Shirl | |
| Chuck Connors | ... | Tab Fielding | |
| Joseph Cotten | ... | William R. Simonson | |
| Brock Peters | ... | Chief Hatcher | |
| Paula Kelly | ... | Martha | |
| Edward G. Robinson | ... | Sol Roth | |
| Stephen Young | ... | Gilbert | |
| Mike Henry | ... | Kulozik | |
| Lincoln Kilpatrick | ... | The Priest | |
| Roy Jenson | ... | Donovan | |
| Leonard Stone | ... | Charles | |
| Whit Bissell | ... | Gov. Santini | |
| Celia Lovsky | ... | The Exchange Leader | |
| Dick Van Patten | ... | Usher #1 | |
In 2022, Earth is overpopulated and totally polluted; the natural resources have been exhausted and the nourishment of the population is provided by Soylent Industries, a company that makes a food consisting of plankton from the oceans. In New York City, when Soylent's member of the board William R. Simonson is murdered apparently by a burglar at the Chelsea Towers West where he lives, efficient Detective Thorn is assigned to investigate the case with his partner Solomon "Sol" Roth. Thorn comes to the fancy apartment and meets Simonson's bodyguard Tab Fielding and the "furniture" (woman that is rented together with the flat) Shirl and the detective concludes that the executive was not victim of burglary but executed. Further, he finds that the Governor Santini and other powerful men want to disrupt and end Thorn's investigation. But Thorn continues his work and discovers a bizarre and disturbing secret of the ingredient used to manufacture Soylent Green. Written by Claudio Carvalho, Rio de Janeiro, Brazil
This was a fairly interesting film when it first came out. I showed what the world could look like in the near future if population growth went unchecked and the awful consequences we would pay. The story itself was fairly engrossing especially the climax of the film as Thorn finds out the real source of the miracle food. But, perhaps the most memorable aspect of this film was that this was the final film of the late great Edward G. Robinson. He gave a fine performance as Saul, and his death scene was very touching, even for a movie like this.