Assignment: Kill Castro was originally released as Cuba Crossing. Stuart Whitman stars as a mercenary hired to "off" the Cuban dictator. He soon discovers that he will be immediately expendable once the deed is done, and that co-stars like Robert Vaughn should not automatically be trusted. Raymond St. Jacques, Woody Strode and Caren Kaye are among the good actors who appear fitfully in the film; the bulk of the story, however, is carried by such inexpensive unknowns as Mary Lou Gassen. Don't miss jewelry-bedecked pop star Monty Rock III as a "cruiser"--and we don't mean the Evinrude variety. A giveaway that Assignment: Kill Castro had trouble finding an audience is its plethora of alternate titles; in addition to Cuba Crossing, the film was also known as Kill Castro, The Mercenaries and Sweet Violent Tony.
~ Hal Erickson, All Movie Guide