Autoimmune hemolytic anemia (AIHA) is a well-known complication of chronic lymphocytic leukemia (CLL). In recent years the anti-CD20 monoclonal antibody rituximab has been used for the therapy of steroid-refractory AIHA and autoimmune thrombocytopenia, either idiopathic or in association with CLL. We report the results of rituximab treatment for 14 patients suffering from CLL-associated AIHA. They developed a direct antiglobulin test positive AIHA at a mean time of 47 months (range 0-135 months) from the diagnosis of CLL. In 3 cases AIHA was diagnosed at the same time as CLL. Only 1 patient had fludarabine-related AIHA. All patients received steroids as first-line treatment. At a mean time of 46 days (range 1-210 days) from the diagnosis of AIHA all patients received rituximab at a dosage of 375 mg/m(2)/weekly for 4 weeks. All patients except 3 (2 died of cardiac failure or sepsis soon after the third cycle and 1 HCV-positive patient experienced a rise in serum amino transferases) completed the scheduled four programmed cycles. First injection side effects of rituximab were minimal. All but 2 patients showed an increase in hemoglobin levels in response to rituximab (mean value 3.6 g/dl; range 0.7-10 g/dl) and a reduction in the absolute lymphocyte count and lymph nodes and spleen volume. Nine patients required packed red cell transfusions before starting rituximab; 5 no longer needed transfusions just after the second cycle and another patient after the fourth cycle. Three patients (22%) were considered to fully respond and 7 (50%) only responded partially. At a mean follow-up of 17 months, 8 patients were still alive, 6 of them transfusion-free. Our results prove that the anti-CD20 monoclonal antibody is an effective and well-tolerated alternative treatment for CLL-associated AIHA.