Theoretical considerations and preliminary results of clinical trials support the earlier use of autologous bone marrow transplantation (ABMT) in poor prognosis non-Hodgkin's lymphoma (NHL). A prognostic analysis of 50 patients with intermediate or high grade NHL younger than 60 years, who achieved at least one complete remission and were not treated with BMT, was performed. Patients with bulky tumor at diagnosis and/or serum LDH greater than or equal to 600 U/l do poorly with conventional chemotherapy. Twelve patients with these high-risk initial characteristics in first complete remission (CR) and six patients in second or third CR were treated with cyclophosphamide (60 mg/kg x 2) and total body irradiation (1000-1200 cGy) followed by ABMT. Overall disease-free survival was 65% at a median follow-up of 35 months. No differences were found between the first and later CR patients. The rate of toxic death was 11%. Disease-free survival after first CR was better for 1st CR ABMT patients than for a historical chemotherapy control group with similar poor prognosis features (p = 0.008). These results support the use of ABMT in selected, high-risk NHL patients in first CR.