Improved survival has been observed in poor-risk diffuse large B-cell lymphoma (DLBCL) patients treated with high-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) in first complete remission. Retrospective studies have suggested that HDT with ASCT can improve survival also in partial responders but some doubts about the advantage of intensive therapy in such patients still remain. We evaluated retrospectively the results of HDT and ASCT in 55 patients with confirmed DLBCL treated between May 1999 and July 2006. Thirty-six patients (65%) showed partial remission (PR) and 19 patients (35%) reached complete remission (CR) after induction treatment with (44%) or without (56%) concomitant rituximab (R) immunotherapy. After HDT and ASCT, 69% of patients fulfilled the criteria of CR, 22% had unconfirmed CR (CRu), 7% remained in PR and 1 patient (2%) relapsed. Twenty patients in PR after the induction treatment reached CR after ASCT, 12 other PR patients achieved CRu. The 5-year event-free survival (EFS) of the 55 transplanted patients was 76% (95% confidence interval /CI/, 63% to 89%) and the 5-year overall survival (OS) was 85% (95% CI, 73% to 97%). The EFS and OS rates differed significantly only between patients younger than 40 years and older groups (p=0.022 and p=0.046, respectively). On univariate analysis of prognostic factors, EFS and OS were not affected by any of the following: age, sex, stage, subtype of DLBCL, initial lactate dehydrogenase, beta-2-microglobulin and serum thymidine kinase levels, International Prognostic Index (IPI) and age-adjusted IPI scores, induction treatment with or without rituximab and type of primary therapeutic response (CR vs PR). These results show that first-line HDT and ASCT for adults up to the age of 65 years with poor-risk DLBCL is a feasible and effective treatment option even in the era of R-chemotherapy in CR as well as for patients in PR.