A young woman who had a delivery history 3 months previously presented with dyspnea and orthopnea. Initial findings of physical examination, chest radiography, and echocardiogram showed typical congestive heart failure with severe left ventricular (LV) dysfunction. At first, we considered peripartum cardiomyopathy because she had given birth to a baby 3 months previously. However, even though we massively tried conventional drug therapy for 10 days, the patient still remained with refractory heart failure. We performed additional laboratory studies such as complement level and autoantibodies, of which the results supported systemic lupus erythematosus. We could make the diagnosis of acute lupus myocarditis and treated her with corticosteroid. The symptoms were dramatically disappeared and LV function also improved.