Objectives : Sipjeondaebo-tang is a medicine traditionally prescribed as a restorative. The aim of this study was to investigate the single oral dose toxicity and safety of extract of fermented Sipjeondaebo-tang in ICR mice. Methods : In single oral dose toxicity study, non-fermented or fermented Sipjeondaebo-tang were administered by oral gavage to ICR mice (5 males, 5 females) at single doses of varying concentrations: 1250, 2500 and 5000 mg/kg. Changes of body weight, general behavior, adverse effects and mortality were determined throughout the experimental period. Hematological parameters, organ weights and necropsy findings were evaluated at the end of the experiment. Results : There were no mortality or signs of toxicity in single oral dose toxicity studies. There were also no significant differences in body weight, organ weight, or hematological parameters between the treatment and control groups. Conclusions : Fermented Sipjeondaebo-tang did not cause remarkable adverse effects in ICR mice. The oral lethal dose of fermented Sipjeondaebo-tang is more than 5000 mg/kg and no-observed-adverse-effect level (NOAEL) of the extract for both male and female mice is 5000 mg/kg.