A 54-year-old man had a severe case of cicutoxin poisoning following the ingestion of water hemlock (Cicuta maculata). The administration of thiopentone sodium by continuous intravenous infusion proved the optimum method of controlling the gross and irregular body movements and of managing the metabolic acidosis and the cholinergic crisis characteristic of this type of poisoning. This report includes a detailed neurologic and biochemical assessment of the condition.