We investigated the addition of rituximab to an intensified salvage program followed by a myeloablative course with autologous stem cell transplantation (ASCT) in patients with relapsed or refractory aggressive non-Hodgkin lymphoma (NHL). Patients with relapsed or progressive aggressive NHL were treated with two cycles of conventional salvage chemotherapy (DHAP) followed by high-dose sequential chemotherapy (cyclophosphamide, methotrexate with vincristine and etoposide) and a final myeloablative course (BEAM) with ASCT. Rituximab (375 mg/m(2)) was administered at each treatment cycle. This cohort was compared with a historical control group of patients treated with the same chemotherapy but without rituximab. Patients from both groups were matched by duration of first remission and lactate dehydrogenase serum levels. Forty-five patients were treated with chemotherapy and 22 with immunochemotherapy. The overall response rates (ORR) at the final evaluation were 63% for the immunochemotherapy group and 42% for the chemotherapy group (p = 0.330). In the historical controlled analysis freedom from second failure (FF2F) at 2 years in the immunochemotherapy group was 57% and overall survival (OS) was 77%. FF2F in the chemotherapy group was 18% (p = 0.0051) and OS was 37% (p = 0.0051). In the matched-pair analysis, FF2F was 58% in the immunochemotherapy group compared to 16% in the chemotherapy group (p = 0.0517); OS was 74 vs 33%, respectively (p = 0.0424). The toxicity was tolerable and comparable in both groups. The addition of rituximab to an intensified salvage chemotherapy regimen seems to improve the prognosis. However, only prospective randomized trial can offer sufficient data of the value of rituximab in relapsed and refractory aggressive NHL.