The battle proved to be the bloodiest of the war and the bloodiest battle involving American troops since the Vietnam War. Comparisons with the Battle of Hue City and the Pacific campaign of World War II were made. Coalition forces suffered a total of 107 killed and 613 wounded during Operation Phantom Fury. U.S. forces had 54 killed and 425 wounded in the initial attack in November. By 23 December when the operation was officially concluded, the casualty number had risen to 95 killed and 560 wounded. British forces had 4 killed and 10 wounded in two separate attacks in the outskirts of Fallujah. Iraqi forces suffered 8 killed and 43 wounded. Estimates of insurgent casualties are complicated by a lack of official figures. Most estimates place the number of insurgents killed at around 1,200 to 1,500, with some estimations as high as over 2,000 killed. Coalition forces also captured approximately 1,500 insurgents during the operation. The Red Cross estimated directly following the battle that some 800 civilians had been killed during the offensive. The Iraq Body Count project reported between 581 and 670 civilian deaths resulting from the battle.
The 1st Marine Division fired a total of 5,685 high-explosive 155mm artillery rounds during the battle. The 3rd Marine Air Wing (aviation assets only) expended 318 precision bombs, 391 rockets and missiles, and 93,000 machine gun and cannon rounds.
Fallujah suffered extensive damage to residences, mosques, city services, and businesses. The city, once referred to as the "City of Mosques", had over 200 pre-battle mosques of which 60 or so were destroyed in the fighting. Many of these mosques had been used as arms caches and weapon strongpoints by Islamist forces. Of the roughly 50,000 buildings in Fallujah, between 7,000 and 10,000 were estimated to have been destroyed in the offensive and from half to two-thirds of the remaining buildings had notable damage.
