During the filming of the movie, 2000 Marines acting as extras were suddenly pulled during the Laos crisis.
Charles G. Clarke was the original cinematographer, but soon after he arrived in Kyoto, Japan, for some location shooting, he suffered a heart attack and was sent back to the US. Lucien Ballard replaced him.
Battle scenes were filmed on Okinawa substituting for Korea.
When President John F. Kennedy was considering directors to make the film that would become PT 109 (1963), he screened MARINES, LET'S GO as a sample of Raoul Walsh's work. Kennedy didn't like the film, and Walsh didn't get the job.