The harmful effects of some Chinese herbal medicines (CHM) have become a cause for concern among the medical profession and the general public in Hong Kong. From 1989 to 1993, at least 33 patients were treated in the Prince of Wales Hospital because of severe poisoning by CHM. Of these, 20 presented with clinical features typical of aconitine poisoning following the ingestion of "chuanwu", the main root of Aconitum carmichaeli, or "caowu", the root of Aconitum kusnezoffii. Strict legislation controlling the use of chuanwu and caowu alone would have prevented many of the severe poisonings by CHM in Hong Kong.