Fifty-eight fatal cases of Guillain-Barré syndrome (GBS) were reported during the 1976 to 1977 National Influenza Program: Thirty-two (58%) of these patients had received the A/New Jersey influenza vaccine. The mean interval from vaccination to onset was 3.9 weeks, and the incidence of preceding illness in vaccinated or unvaccinated patients was similar. Fifty-eight percent had at least one chronic disease before onset. The clinical features were similar in vaccinated and unvaccinated patients. Most deaths followed medical complications of respiratory paralysis: Fifteen had pneumonia, 29 (83%) died suuddenly, 15 had sudden arrhythmias or hypotension, and 7 had myocardial infarction or pulmonary embolus.