In intravascular lymphoma (IVL) tumor cells are initially restricted to vascular lumina. Neurological syndromes predominate and are caused by ischemia as well as tumor infiltration into the nervous system. Ante mortem diagnosis is challenging and frequently impossible. Chemotherapy is effective if started prior to ischemic damage. Over a three year period, we have diagnosed IVL in seven patients. Tissue diagnosis could be accomplished in only three cases. Forthose in whom tissue diagnosis failed we based our diagnosis on clinical presentation, typical magnetic resonance imaging findings, spinal fluid cytopathology, and molecular analyses. Six patients were treated with methotrexate chemotherapy alone or in combination with CHOP. Three patients are in complete remission 9-20 months after initial diagnosis. Another patient achieved a partial response. Two patients died due to progressive disease shortly after initiation of treatment. Grade III toxicity was observed in only 4 of 61 cycles. Based on a small retrospective series of patients, we conclude that methotrexate is a well tolerated and effective agent for the treatment of IVL.