High-dose chemotherapy conditioning regimens followed by autologous stem cell transplantation generally provide good results in non-Hodgkin lymphoma. We have evaluated the effects of a high-dose regimen comprising thiotepa, etoposide and carboplatin. After debulking and mobilization with high-dose cyclophosphamide or other schedules, forty-five patients at various disease stages were conditioned with thiotepa, etoposide and carboplatin prior to autologous stem cell transplantation. The overall response rate was 77.8% (30 CR, 66.7%; 5 PR, 11.1%). Ten patients (22.2%) did not respond. Two patients (4.4%) died from transplant-related complications. The mean 5-year overall survival was 71.1%: 12 patients relapsed within the first 5 years of follow-up. The overall response rate and 5-year overall survival were better for patients with an International Prognostic Index (IPI) 1 at diagnosis than for those with IPI 2 and IPI 3 (P<0.005 for all). The thiotepa, etoposide and carboplatin conditioning regimen for autologous stem cell transplantation in non-Hodgkin lymphoma has a good anti-lymphoma effect and provides encouraging results in terms of response to treatment and 5-year overall survival. Its good tolerance and acceptable toxicity suggest that it may a very useful in the management of non-Hodgkin lymphoma.