Confirmed cases of poisoning resulting from the ingestion of Colchicum autumnale in mistake for Allium ursinum were analysed retrospectively. The study included 32 patients between 27 and 90 years. The severity of the intoxication was graded on the basis of the poisoning severity score (PSS). All the patients developed diarrhea and/or vomiting after a latency period of between 2 and 24 h. All those patients with a latency of > 9 h suffered only mild poisoning. If the leaves were boiled before being eaten, 64% of the patients suffered moderate, severe or fatal poisoning; when the leaves were eaten raw, only 33%. It is presumed that heating may promote the liberation of colchicines from the plant. Eight of the nine patients with severe or fatal poisoning were older than 65 years. A possible cause of the more serious course in the elderly may be a decrease in renal clearance. In addition, a diminished sense of smell may allow the absence of the typical garlic smell and taste of Allium ursinum to go unrecognised.