The aim of this study was to determine the feasibility, efficacy and toxicity of the combined therapy consisting of cladribine (2-CdA), mitoxantrone and cyclophosphamide (CMC regimen) in patients with refractory or relapsed non-Hodgkin's lymphoma (NHL). Thirty six patients, 14 with mantle cell lymphoma (MCL), 10 with diffuse large B-cell lymphoma (DLBCL), 5 with follicular lymphoma (FL), 3 with small lymphocytic lymphoma (SLL), and 4 with T-cell lymphoma were enrolled to the study. The CMC protocol consisted of 2-CdA at a dose of 0.12 mg/kg in a 2-hour infusion on days 1 through 3, mitoxantrone 10 mg/m(2) i.v. on day 1 and cyclophosphamide 650 mg/m(2) i.v. on day 1. The CMC courses were repeated at intervals of 4 weeks. Thirty three patients were available for evaluation of response. Overall response rate (OR) was 58% (95% CI, 41--75%). Seven patients (21%; 95% CI, 7--35%) achieved a complete response (CR) and 12 patients (36%; 95% CI, 20--52%) achieved a partial response (PR). Seven of 19 patients with CR/PR are still in remission with a median follow-up of 3 months (range, 2-17 months). The median failure-free survival (FFS) was 5 months (range, 2-17 months). The median overall survival (OS) for the entire group was 9 months (range, 0.1-7 months). There was a significant difference in OS between responders and nonresponders after CMC therapy (log rank test, P = 0.015). When different disease status before CMC treatment was considered, a trend toward longer survival of recurrent patients was observed (log rank test, P = 0.08). Grade 3-4 neutropenia developed in 14 (39%) patients, and 16 episodes (15%) of grade 3-4 infections were observed. Grade 3-4 thrombocytopenia or anemia was seen in 9 patients (25%) and 10 patients (28%), respectively. The results of our study show that the CMC regimen is effective salvage therapy with acceptable toxicity in heavily pretreated patients with NHL including MCL and DLBCL.