Three women became ill within a few hours after eating a common meal of tuna fish, bread, salad dressing, and coffee. One died 13 hours after onset; another died five days after onset; the third woman, who ate very little, survived a brief mild illness. The clinical diagnosis was botulism. This was confirmed by epidemiological, pathological, and laboratory studies, with the finding of type E<i>Clostridium botulinum</i>. The botulinus toxin came from the canned tuna fish. The exact manner of contamination of the tuna has not been found. Treatment consists of supportive therapy and type-specific antiserum. Though type E botulism has been much less common than types A or B in this country, it may become more frequent. It is recommended that a polyvalent antiserum, containing types A, B.<i>and E</i>, be made available in quantities sufficient to meet future emergencies. Clinical diagnosis of botulism must be made quickly and type-specific antiserum must be administered early, without waiting for bacteriological evidence.