Significant toxicity can result from ingestion of certain species of the Zigadenus plant, an herb occasionally confused with nontoxic wild onions. A 50-year-old man inadvertently ingested Z paniculatus and presented to the emergency department with profound gastrointestinal toxicity, hypotension, and bradycardia. The pathophysiology and management of Zigadenus poisoning are reviewed. Emergency physicians, particularly in rural areas, should be aware of the morbidity caused by ingestion of some Zigadenus species.