A large outbreak of foodborne botulism provided an opportunity to study the recovery from type A botulism in a group of 27 patients. Patients were interviewed either nine or 13 months after the outbreak, and a written questionnaire was mailed at 24 months, to obtain information on each patient's symptom complex and on subsequent symptom resolution. Recovery from symptoms of botulism was slow. Patients reported that resolution of 50 per cent of their original symptoms occurred by an average of 5 months. Thirteen of 14 patients contacted 13 months after onset of botulism reported some persistent symptoms. This study, although limited to interview data, strengthens the concept of a prolonged recovery phase in botulism, as previously suggested in individual case reports. Physicians and other health workers caring for patients with botulism should anticipate physical and psychological problems resulting from a lengthy and difficult convalescent period.