Jin Bu Huan (JBH) is a traditional Chinese herbal product used as a sedative and analgesic. During 1993, public health and health-care providers in Colorado reported three children with unintentional overdoses of JBH that caused central nervous system and respiratory depression with rapid onset of life-threatening bradycardia. Subsequently, the first cases of acute hepatitis attributed to use of JBH were diagnosed in three women in Los Angeles during July and August 1993. Patients 1 and 2 were referred to a Los Angeles hepatology clinic by their physicians; patient 3 was identified by patient 2. All three patients had purchased JBH at the same health-food store. This report summarizes the investigation of these cases.