Proficient director of mainstream international and Hollywood genre features. Cosmatos's first memorable feature was "Massacre in Rome" (1973), a solid WWII drama starring Richard Burton and Marcello Mastroianni as, respectively, a Nazi colonel and a priest. He began his entertainment career working with a leading figure in international cinema, as an assistant director on Otto Preminger's epic "Exodus" (1960). In the late 70s, Cosmatos began to specialize in big-budget Hollywood and international action films, starting with the technically flashy, enjoyably old-fashioned adventure-on-a-train film, "The Cassandra Crossing" (1977), and followed up with "Escape to Athena" (1979), a lesser WWII action yarn starring Roger Moore and Telly Savalas.

One of Cosmatos's more notable films was "Rambo: First Blood Part II" (1985), a vigorous sequel starring Sylvester Stallone as tortured Vietnam Vet John Rambo. Condemned as a reactionary rewriting of recent American history by some critics, the film was a huge and influential success. Cosmatos, meanwhile, has pointed to the film as a positive force in raising our consciousness about getting the remaining American POWs and MIAs returned home.

Cosmatos reteamed with Stallone for the carnage-filled yet forgettable "Cobra" (1986) and attempted to cash in on the success of "Alien" with "Leviathan" (1989), an underwater sci-fi pic. After a few years off, Cosmatos returned to features, taking over the reins of "Tombstone" (1993), yet another retelling of the Wyatt Earp story starring a youthful ensemble headed by Kurt Russell and Val Kilmer.