The effect of capsaicin on the toxicity of ethanol in mice were studied. Capsaicin was administered i.p. every other day for 4 weeks and 5% ethanol was provided ad libitum by tap water for 4 weeks. The administration of capsaicin 3.0 mg/kg showed the increase of body weight gain, ratio of liver wt./body wt., s-GPT. s-triglyceride and s-cholesterol, and showed the decrease of BUN as compared to control group. Capsaicin administered 3.0 mg/kg showed severe moth eaten appearance. eosinophilic necrosis and cholangitis in mouse liver The administration of 5% ethanol showed the decrease of body weight gain, ratios of liver, kidney and spleen wt./body wt., s-tryglyceride and s-cholestrol. Ethanol administered 5% solution showed little fatty change, moth eaten appearance, Kupffer cell proliferation, spotty necrosis and nuclear regeneration. The administration of capsaicin and ethanol together decreased the influence of ethanol on body weight gain, ratios of liver, kidney and spleen wt./body wt., s-triglyceride and s-cholesterol, and showed the less severe moth eaten appearance, eosinophilic necrosis and cholangitis. It might be concluded that the administration of capsaicin and ethanol together decreased the toxicity caused by capsaicin or ethanol respectively.