Abstract: OBJECTIVE To learn from the cases of medical damage liability disputes, and promote rational drug use. METHODS Acyclovir was selected as model drug, and 6 cases in web of China judgements online were chosen using the "medical damage liability disputes" with drugs limited to "acyclovir", and the descriptive analysis on 6 cases was done. RESULTS The 6 cases were deficient in rational drug use, duty of cautious attention and duty of informed consent. There were also deficiencies in the prediction, information, avoidance and treatment of adverse drug reactions. CONCLUSION Pharmacists should assist doctors to do a duty of cautious attention and informed consent to reduce medical damage liability disputes related to pharmacy.