Objectives: To provide information on the safety of GST (GamiSasangja-tang; CnidiiFructus, Sophora Root, Angelica Gigas Root, Clematidis Radix, Stemonae Radix, Spirodelae Herba), we carried out a 13-week repeated oral dose toxicity and a 4-week recovery test of GST in Sprague-Dawley rats. Methods: Female and male rats were treated with GST at oral doses of 1,250, 2,500, and 5000 mg/kg. The GST was administered for 13 weeks. Mortality, clinical signs, body weight changes, food consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights and histological markers were monitored during the study period. The rats were then monitored for 4 extra weeks to determine recovery time after the study period. Results: We found no mortality or abnormalities among clinical signs, body weight, food consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights or histological markers in any of the rats tested. Conclusions: The no-observed adverse effects level (NOAEL) is considered as over 5000 mg/kg for male and female rats.