Botulism is a rare but serious paralytic disease caused by botulinum toxin. We report an outbreak of type B botulism in Taiwan in 2006. There were five cases involved in this outbreak. They present ileus and acute cranial nerve dysfunction including dysphagia and blurred vision. One of them had severe neurologic impairment and required mechanical ventilatory support. No patient received antitoxin administration because of delayed diagnosis. The food specimen revealed positive botulism toxin B. There were no fatalities. Consumption of fermented food was significantly associated with this outbreak. We also reviewed the characteristics of cases with botulism in Taiwan since 1985.