Objectives : Traditional medicine Oryeong-san (ORS) has been prescribed for a long time to treat light fever, thirst, dysuria, and accompanying edema. However, the acute toxicity and safety were not reported. In this study, we evaluated the potent acute toxicity and safety of ORS. Methods : ICR mice were used to evaluate acute toxicity and safety by oral administration of 0, 500, 1,000, 2,000mg/kg of ORS. Mortality, body weight, and clinical symptoms were observed, and organ weight and blood biochemical parameters were analyzed after necropsy. Results : We found no mortality and no toxic or abnormal clinical symptoms by administration of ORS. Comparing with control group, no significant alterations in organ weight and blood biochemical parameters were observed. Conclusions : ORS recognized as safe and non-toxic medicinal material, and median lethal dose considered to be over 2,000 mg/kg in both male and female ICR mice.