Warm-type idiopathic autoimmune hemolytic anemia (AIHA) is a relatively common hematologic disorder resulting from autoantibody production against red blood cells. Steroids represent the first-line therapeutic option, and immunosuppressive agents as well as splenectomy are used for refractory cases. Recently, the anti-CD20 monoclonal antibody rituximab has been shown to control autoimmune hemolysis in patients with refractory chronic disease. We report results from a retrospective analysis of 11 adult patients receiving rituximab for steroid-refractory AIHA of the warm type at a mean age of 55 yr (range 23-81 yr). All patients were given methyl-prednisolone as first-line treatment and some of them also received azathioprine and intravenous high-dose immunoglobulins. One patient underwent splenectomy. All patients were considered refractory to steroids and/or immunosuppressive drugs and all were then given weekly rituximab (375 mg/m(2)) for four consecutive weeks. An increase in hemoglobin (Hgb) levels in response to rituximab, with a mean increment of 3.3 g/dL (95% CI 2.1-4.4), was observed in all cases. Four patients required packed red cell transfusions before starting rituximab and all became transfusion-free. At a mean follow-up of 604 d (range 30-2884 d) since the treatment of AIHA with rituximab, all patients are alive, eight (73%) of them in complete remission (CR) and three (27%) in partial remission (PR). A moderate hemolysis still persisted in six (54%) patients. In conclusion, our experience clearly demonstrates that anti-CD20 monoclonal antibody rituximab is an effective and safe alternative treatment option for idiopathic AIHA, in particular, for steroid-refractory disease.