The aim of this study was to investigate the acute oral toxicity of fermented Scutellariae Radix (JKTMHGu-100) in rats and dogs. JKTM-HGu-100 was orally administered at a dose of 2,000 mg/kg in Sprague-Dawley rats. An escalating single-dose oral toxicity test in beagle dogs was performed at doses of 500, 1000, and 2000 mg/kg with 4-day intervals. Clinical signs, changes in body weight, mortality, and necropsy findings were examined for 2 weeks following oral administration. No toxicological changes related to the test substance nor mortality was observed after administration of a single oral dose of JKTM-HGu-100 in rats or dogs. Therefore, the approximate lethal dose (LD) for oral administration of JKTMHGu-100 in rats was considered to be over 2,000 mg/kg, and the maximum tolerance doses (MTDs) in rats and dogs were also estimated to be over 2,000 mg/kg. These results indicate that JKTM-HGu-100 shows no toxicity in rodents or non-rodents at doses of 2,000 mg/kg or less.