Mumefural is a bioactive compound derived from the processed fruit of Prunus mume Sieb. et Zucc., a traditional health food; however, its safety has not been evaluated. We investigated the toxicity of mumefural through single and repeated oral administration at doses of 1250, 2500, and 5000 mg/kg in Institute of Cancer Research (ICR) mice. The acute toxicity assessment was not associated with adverse effects or death. Similarly, the subacute (four weeks) toxicity assessment did not reveal any mumefural-associated mortality, abnormal organ damage, or altered clinical signs, body weight, food consumption, or hematological parameters. However, albumin/globulin ratio and chloride ion levels were significantly increased in male mice treated with mumefural at ≥ 2500 mg/kg. Female mice exhibited significantly higher levels of chloride, sodium, and potassium ions, at a dose of 5000 mg/kg. Furthermore, the administration of 2500 and 5000 mg/kg mumefural decreased the absolute weight of spleen in male mice. These findings indicated that the approximate lethal dose of mumefural in ICR mice was > 5000 mg/kg. No significant mumefural toxicity was observed at ≤ 5000 mg/kg. Our findings provide a basis for conducting future detailed studies to evaluate reproductive, neurological, genetic, and chronic toxicity of mumefural.