The American alligator inhabits bodies of fresh water in Florida and other southeastern states. Although attacks on pets are frequent, alligator attacks on humans are relatively rare because of the animal's natural fear of man. Because of the rarity of attacks on humans, the pathologic findings and pathophysiology of death in such cases have not been well characterized in the literature. We report three cases of fatal alligator attacks that occurred in southwest Florida, each with different pathologic findings and mechanisms of death. Although the cause of death in each case was attributed to the alligator attack, the mechanisms of death differed and included exsanguination because of amputation of an extremity, overwhelming sepsis, and drowning. These cases illustrate the varied pathophysiologies associated with deaths due to alligator attacks on humans and the features that distinguish alligator bites from those of other aquatic predators.