The objective of this study was to evaluate the single oral dose toxicity of Polygalae Radix (PR) in male and female mice. PR extract (yield = 18.6%) was administered to ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines (2009-116, 2009). Animals were monitored for the mortality and the changes in body weight, clinical signs and gross observation during 14 days after dosing. Upon necropsy, organ weight and histopathology of 14 principal organs were examined. It was observed that there were no mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations against 14 principal organs related to PR extract up to 2,000 mg/kg. Therefore, 50% lethal dose ($LD_{50}$) and approximate LD of PR aqueous extracts after single oral treatment in female and male mice were considered over 2000 mg/kg the limited dosages recommended by KFDA Guidelines, respectively.