Two of three persons who ate lunch together became ill with symptoms characteristic of botulism. One died before botulism was suspected and before specimens could be collected for laboratory testing, but a serum specimen from the other patient, who survived, yielded botulinal toxin, type A. The third person remained asymptomatic, but Clostridium botulinum type A was cultured from his stool. The three persons had shared two canned foods: home-canned green beans and commercially canned beef stew. The green beans were initially assumed to be the cause of the outbreak. However, the empty stew can was recovered from the garbage, and washings from the can yielded C botulinum, type A, and its toxin.