Objectives: This study was to evaluate the single dose toxicity of Sobokchuko-tang (SBC) in male and female mice. Methods: Aqueous extract of SBC (yield=6.60%) was administered to female and male 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. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 14 principle organs were also examined. Results: we could not find any SBC treatment related mortality and clinical signs, changes in the body and organ weights, gross findings and changes in histopathology of principle organs, except for pharmacological immunomodulatory effects related findings including significant increases of submandibular lymph node weights, hypertrophy and hyperplasia of lymphoid cells in the submandibular lymph nodes restrictly detected in 2,000 mg/kg treated female and male mice with some sporadic accidental findings. Conclusions: The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of SBC aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines, and can be safety used in clinics.