Television movie debut for Lee Marvin. This is despite appearing in a number of television series episodes and the movie The Killers (1964), which was originally made for television but ended up being released theatrically because it was thought to be too violent for TV.
This is the only movie sequel that Lee Marvin ever appeared in. His character Major John Reisman did not appear in the next two Dirty Dozen TV movie sequels, The Dirty Dozen: The Deadly Mission (1987) and The Dirty Dozen: The Fatal Mission (1988). His character was replaced by Major Wright played by Telly Savalas. Savalas had appeared in the original The Dirty Dozen (1967) movie as Archer Maggott where his character was killed-off.
Ernest Borgnine is the only actor from the original The Dirty Dozen (1967) movie to appear in all four "Dirty Dozen" movies.
As they're departing for training camp, Reisman asks Bowren "What do you think?" to which he replies "I think the first chance one of these guys gets, he'll shoot the Major in the back." That's the same exchange the two had in The Dirty Dozen (1967).