The scene in which a sailor falls from a ship and is left in the water as the fleet steams toward Iwo Jima actually happened. The incident is described in "Iwo" by Richard Wheeler, himself a veteran of the fighting. Quote: "According to Coast Guardsman Chet Hack of LST 763: 'We got the man-overboard signal from the ship ahead of us. We turned to port to avoid hitting him and threw him a life preserver, but had orders not to stop. We could not hold up 24 ships for one man. Looking back, we could see him waving his arms, and it broke our hearts that we couldn't help him. We hoped that one of our destroyers or other small men-of-war that were cruising around to protect us would pick him up, but we never heard that they did.' "
At the Cannes Film Festival, filmmaker Spike Lee criticized director Clint Eastwood for not displaying African-American marines who had fought on Iwo Jima. Eastwood's response was that the movie was about the marines who raised the flag on Mount Suribachi. He went on to explain that although African-Americans did fight on Iwo Jima, the Marine Corps was segregated during WWII, and none of the men who raised the flag were black. Eastwood finally told Lee to "shut his face". Through the media, Lee responded that Eastwood was being an angry old man. Lee was filming Miracle at St. Anna (2008) at the time, a film about four black soldiers fighting WWII in Italy.
The original of the top photograph in the stack of Japanese atrocities is held in the Australian War Memorial. It is dated 24 October 1943, was taken in Aitape, New Guinea, and shows Sergeant Leonard G. Siffleet, about to be beheaded with a sword by Yasuno Chikao.
Clint Eastwood tried to option "Flags of Our Fathers" after the book by James Bradley and Ron Powers was published in May 2000. However, Steven Spielberg had already bought the rights that summer, and in early 2001, had assigned its adaptation to the screenwriter William Broyles Jr.. Spielberg wasn't satisfied with the resulting screenplay and it laid dormant until he met with Eastwood at the Governor's Ball after the 2004 Oscar. After that, Eastwood took charge as the director with Spielberg as the producer.
Actual Marines from the 5th Marines were used as extras during filming aboard ship as well as the the training work up. The extras who were actual Marines can be best seen climbing up and down the cargo nets.
'Flags of Our Fathers' cost $55 million although it was originally budgeted at $80 million. In a 2006 interview Paul Haggis stated that Clint Eastwood had shot the movie in just over 50 days, or nearly half the original shooting schedule. Variety subsequently downgraded the price-tag to $55 million. The budget for the companion piece Letters from Iwo Jima (2006) was officially credited at $20 million but again, according to Variety, the actual cost was "under $70 million" for both movies combined (this would place the cost of 'Letters' as $15 million). It is possible that WB inflated the budget as part of its campaign when it became evident that 'Letters' had Academy Award potential (the same thing happened in 2004 with 'Million Dollar Baby'). As of April 2007 'Flags' and 'Letters' had a combined worldwide theatrical gross of $135 million, with 'Flags' having performed, according to Variety, "very strongly" in its home video bow.
David Rasche appears in the film in a cameo role. Rasche is famous for his lampoon of Clint Eastwood's "Dirty Harry" character in the sitcom Sledge Hammer! (1986). Eastwood is known for his sense of humor and apparently liked the show.
The newspapers containing the famous photograph are, in order of being delivered, the New York Times, the Los Angeles Times, the Hartford Courant, the San Antonio Express, and lastly the Washington Post.
Two actors in the film have been linked before. Len Cariou, who played Mr. Beech, and George Hearn, who played Walter Gust. Cariou originated the title role of Sweeney Todd on Broadway was succeeded in the part by Hearn.