William A. Wellman, nicknamed "Wild Bill", was a fighter pilot in World War I and hated the infantry, and therefore had no interest in making a film about them. Producer Lester Cowan tried several times to convince Wellman to direct the film, including showing up uninvited at Christmas with gifts for Wellman's children. Wellman finally agreed to take the job only after meeting and spending several days with Ernie Pyle at Pyle's home in New Mexico, where he saw how much former infantrymen revered him.
Gen. Dwight D. Eisenhower called this the finest war film he had ever seen.
Several of the humorous lines spoken by G.I.s in the film are taken, uncredited, from WWII cartoonist Bill Mauldin's "Willie and Joe" characters.
The extras in the film were real American GIs, in the process of being transferred from the war in Europe to the Pacific. Many of them were killed in the fighting on Okinawa - the same battle in which Ernie Pyle was killed by a Japanese machine gunner - never having seen the movie in which they appeared.
War correspondent Ernie Pyle acted as advisor to the film. Pyle was killed not long after the film was completed.