Objectives : The aim of this study was to evaluate the single oral dose toxicity and safety of Bojungikgi-tang (Buzhongyiqi-tang) and fermented Bojungikgi-tang (Buzhongyiqi-tang) extracts in male and female ICR mice. Methods : In the single oral dose toxicity study, non-fermented and fermented Bojungikgi-tang (Buzhongyiqi-tang) were administered to male and female ICR mice as an oral dose of 1250, 2500 and 5000 mg/kg. Changes of body weights, general behaviors, adverse effects and mortality were determined throughout the experimental period. Hematological parameters, serum chemistry, organ weights and necropsy findings were evaluated at the end of the experiment. Results : There was no mortality or sign of toxicity in the single oral dose toxicity study. There were also no significant differences in body weights, organ weights, and hematological parameters, serum chemistry values between treatment and control groups. Conclusions : The results obtained in this study suggest that the 50% lethal dose of fermented Bojungikgi-tang (Buzhongyiqi -tang) in both female and male mice can be considered as well over 5,000 mg/kg, so these medicines can be safe in clinics.