A 38-year-old woman with systemic lupus erythematosus (SLE) presented with liver damage during prednisolone therapy. Because her liver damage did not improve, she was admitted to our hospital. Laboratory findings revealed liver enzyme elevation, impaired glucose tolerance, and insulin resistance. Pathological examination revealed marked diffuse macro and microvesicular fatty infiltration. Because the patient did not consume alcohol, she was given a diagnosis of nonalcoholic steatohepatitis. To improve her insulin resistance, we administered pioglitazone therapy for 1 week; however, subsequent laboratory findings did not indicate any improvement in her liver damage. Assuming that SLE might have caused liver damage, we administered high-dose prednisolone therapy; subsequent laboratory findings indicated that her serum complement titer and the level of liver enzymes improved. Abdominal computed tomography revealed that the Hounsfield number of the liver increased to normal after treatment. Fat infiltration of the liver improved after treatment, which confirmed the fact that her liver damage had been due to SLE.