A patient with probable wound botulism survived on assisted ventilation without guanidine or antitoxin treatment and recovered completely. Diagnosis was aided by electrophysiologic technique indicating a defect in the neuromuscular junction similar to the Eaton-Lambert syndrome. Improvement of the abnormal electrical signs paralleled clinical improvement. A transient defect in staircase formation and dissociation of posttetanic electrical potential and mechanical force suggested a muscular disorder in addition to the known effects of botulism on the terminal neural twigs.