Foodborne botulism is a severe, potentially fatal disease characterized by cranial nerve palsies and descending paralysis. Little is known about signs and symptoms predictive of death from botulism. We studied patients with botulism in the Republic of Georgia, which has the highest reported rate of foodborne botulism in the world. After abstracting medical records of patients with botulism who were hospitalized during 1980-2002, we performed classification-and-regression-tree analysis to identify clinical syndromes predictive of survival and death. We identified records for 706 patients hospitalized for foodborne botulism from 1980-2002. Trivalent antitoxin was administered to 623 patients (88%). Fifty-four (8%) died. Patients with shortness of breath and impaired gag reflex and without diarrhea were 23 times more likely to die than were patients without this syndrome. Validating this clinical prediction rule may help reduce mortality from botulism in Georgia. Validation in other settings could help public health preparations for large outbreaks of naturally occurring or bioterrorism-related botulism.