Symptoms of acute food poisoning developed in eight members of a group who ate lunch at a cafeteria. After brief incubation periods, all affected individuals complained of nausea and abdominal cramps. Four persons promptly experienced vomiting. None of those affected was found to have fever and all recovered with 48 hours. Epidemiologic investigation incriminated macaroni and cheese as a cause of the illness and samples of this food contained large numbers of Bacillus cereus. Previous outbreaks of B cereus emetic food poisoning have been associated with consumption of contaminated fried rice and may occur after ingestion of other foods.