The aim of this retrospective single-center study was to analyze the clinical characteristics and outcome of non-Hodgkin lymphoma (NHL) patients with central nervous system (CNS) involvement and to identify prognostic factors for survival. We searched our hospital records for NHL patients diagnosed with CNS involvement from 1982 to 2004, and 43 patients were identified. The median age was 63 years (range 23-88) and the median Karnofsky performance status was 55% (range 10-90). Treatment of CNS lymphoma included intrathecal chemotherapy in 33 patients (77%), systemic chemotherapy in 25 (58%), and radiotherapy in 16 (37%). Twenty-six patients showed a CNS response. The median survival after CNS manifestation was 5 months (range 2 days-82.5+months). Nine patients achieved long-term survival. Low lactate dehydrogenase (LDH) at CNS manifestation and a CNS response to therapy were favorable independent prognostic factors for survival in multivariate analysis (p = 0.051 and p < 0.0005, respectively), whereas a young age at initial diagnosis, initial CNS involvement, an initially normal LDH, and high-dose chemotherapy for CNS involvement were significant in univariate analysis. In conclusion, long-term survival can be achieved in patients with secondary CNS lymphoma. LDH at CNS manifestation and a CNS response to therapy were significantly associated with survival.