Subacute toxicity of sorbitan trioleate (STO) was carried out using Wistar rats. STO was administered intravenously at dose levels of 12.5, 50.0 and 200.0 mg/kg for 35 days. No influence on general symptom, body weight, food and water consumption and urinalysis were observed. In 200.0 mg/kg group, the hematological examination revealed anemia corresponding to the histological findings of the bone marrow. Biochemical analysis displayed the significant increase and/or decrease of enzyme values in 200.0 mg/kg group. The maximal no-effect level of the STO in Wistar rats was considered to be 50.0 mg/kg.