Patients with malignant central nervous system (CNS) involvement of lymphoma have a poor prognosis with intrathecal chemotherapy and radiation. In this paper, we report the results we obtained in such patients by intravenous chemotherapy with high-dose methotrexate and ifosfamide (HDMTX/IFO). The study involved a review of all patients who received HDMTX/IFO for CNS involvement of malignant lymphoma at our hospital. Therapy consisted of 4 g/m(2) of MTX (4 h infusion on day 1) and 1.5-2 g/m(2)/day of IFO (3 h infusion on days 3-5). The study included 20 patients with a median age of 65 years (range, 30-83) and CNS relapse of a malignant lymphoma. Seventeen patients had been pretreated with up to two chemotherapy regimens. The objective response rate was 90% with 12 complete or unconfirmed complete (CR and CRu) and six partial remissions. All patients had at least stabilization of their neurological symptoms. Myelosuppression was the most common toxicity. The median follow-up time was 14.9 months. The median time to neurological progression was 8.9 months. Twelve patients received subsequent therapy, including high-dose chemotherapy with autologous stem cell transplantation in five cases. The median overall survival was not reached. Systemic chemotherapy with HDMTX/IFO is a feasible and promising treatment modality for CNS relapse of a malignant lymphoma.