- Beam Me Up, Scotty!: The quote "Life is hard enough. It's even harder when you're stupid" is usually attributed to John Wayne in this movie. However, neither he nor anyone else in the movie says the line or any variations. In fact, Wayne never said those words in any of his movies.
- Cast the Expert: A number of actual military personnel portrayed themselves. These included retired Lt. Gen. Holland M. Smith, who was the 5th Amphibious Corps commander and who also acted as a technical advisor; Col. David M. Shoup, U.S.M.C., who received the Medal of Honor; Capt. Harold G. Schrier, U.S.M.C., who commanded the Marines on the Suribachi slopes; Lt. Col. H.P. Crowe, U.S.M.C., who was a battalion commander on Tarawa (the man with the waxed mustache); Pfc. Rene A. Gagnon; Pfc. Ira H. Hayes; and Ph M3c John H. Bradley.
- California Doubling: Most of the movie was filmed at Camp Pendleton (the primary Marine Corps base on the West Coast) and other locations in southern California, even the scenes of the amphibious landings on Tarawa and Iwo Jima. However, these scenes are interspersed with actual combat footage from the invasions of the two islands, which makes the whole thing much more real-looking.
- The Danza: John Wayne as Sgt. John Stryker.
- Irony as She Is Cast: In one scene, Sgt. Stryker instructs Pvt. Choynski how to march and hold a rifle. In real life Hal Baylor was a Marine combat veteran who fought in the battles of Saipan and Tinian, while John Wayne never spent any time in the military.
- What Could Have Been: Kirk Douglas was considered for Sgt. Stryker
Trivia / Sands of Iwo Jima