Although drug induced liver injury caused by herbal medicine is considered to be a frequent problem in Korea, there are only a few reports concerning the hepatotoxicity of herbal medicine. We recently experienced two cases of drug induced liver injury caused by ingestion of Dyctamnus dasycarpus, and one of herbal drug used for antipyretic and analgesic purposes. The first patient, a 48 year old man, was admitted due to jaundice after ingestion of the liquor containing Dyctamnus dasycarpus and some other herbal medications for 4 months. All viral markers were negative on admission, and the elevated bilirubin and transamiase levels normalized 5 months later after cessation of all herbal medications. Ten months after the first admission, he ingested only the liquor containing Dyctamnus dasycarpus, with lesser duration and amount, and was readmitted due to general weakness and fatigue and elevated transaminase (>1,000 IU/L). The elevated transaminase level nearly returned to normal after discontinuing the causative agent. The second patient, a 62 year old man, was admitted due to jaundice after ingestion of Dyctamnus dasycarpus. The elevated bilirubin and transamiase levels normalized 4 months later after cessation of the causative agent. Dyctamnus dasycarpus induced liver injury presents with prolonged course lasting more than several weeks to months. Herbal drug induced liver disease should be considered in differential diagnosis of acute liver injury of unknown cause in Korea and we are also suggesting the necessity of a systematic approach for the study of the herbal drugs. (Korean J Gastroenterol 1998;31:251 - 257)