Twenty-four crew members aboard a Brazilian cargo ship developed gastrointestinal and neurologic symptoms 30 minutes to six hours after eating meat from a large barracuda. Initially, the men had abdominal pain followed rapidly by frequent vomiting and profuse diarrhea. Soon after, they noticed a tingling and burning sensation of the tongue, and several had transient blindness or blurred vision. Epidemiologic and laboratory investigations showed barracuda meat responsible. Large fish have been associated with ciguatera poisoning, and although rare, the poisoning is particularly important to populations whose diets consist largely of fish.