The film was shot in the Philippines, with 1200 soldiers from the Armed Forces of the Philippines, American soldiers of the 1st U.S. Army Special Forces Group at Okinawa and Clark Air Force Base, and cast the leading roles with several Warner Bros. contract stars who were then the leading men of popular programs, but would not be paid extra salary, three stuntmen (Chuck Roberson, Jack Williams, and Chuck Hicks), two Filipino film stars, and the film's technical advisor. Due to bad weather, Fuller shot six days over the allotted 41-day shooting schedule.