Hemophagocytic syndrome (HPS) is a life-threatening disorder characterized by pancytopenia and activation of macrophages. Recently, corticosteroid incorporated in lipid microspheres (liposteroid) has been reported to be taken up by macrophages and to suppress their functions. Here we present a case of systemic lupus erythematosus complicated by HPS that was successfully treated with liposteroid in addition to an oral corticosteroidand intravenoushigh-dose cyclophosphamidetherapy. The serum levels of tumor necrosis factor-a and ferritin that have been reported to be associated with activity of macrophages remarkably reduced after liposteroid administration. This case suggests that liposteroid is useful for the treatment of HPS.