The purpose of this evaluation was to investigate the efficacy of high-dose chemotherapy with thiotepa, melphalan, and carboplatin (TMCb), and of autologous peripheral blood stem cell (PBSC) infusion in patients with aggressive non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD). A total of 42 patients, 23 with intermediate-grade NHL and 19 with HD, received thiotepa (500 mg/m2), melphalan (100 mg/m2), and carboplatin (1050-1350 mg/m2) followed by autologous PBSC infusion. Of 21 patients with more advanced disease, four had primary refractory disease, one was in complete remission (CR)-2, 11 were in first refractory relapse, and five were beyond first relapse. Of 21 patients with less advanced disease, two were in CR-1, four were in CR-2, and 15 were in first responding relapse. In all, 14 patients (33%) had received prior radiotherapy prohibiting a total-body irradiation (TBI)-based conditioning regimen. The projected 2-year probabilities of survival, event-free survival (EFS), and relapse for all patients were 0.65, 0.60, and 0.21 (0.85, 0.80, and 0.10 for patients with less advanced disease and 0.47, 0.42, and 0.33 for patients with more advanced disease). The probability of nonrelapse mortality in the first 100 days was 0.12. Grade 3-4 regimen-related toxicities (RRT) occurred in five of 42 (12%) patients and death due to grade-4 RRT occurred in only one (2.5%) patient. These preliminary data suggest that 0.42% EFS in this study for advanced disease patients is highly encouraging and high-dose TMCb followed by autologous PBSC transplantation is well tolerated as well as an effective regimen in patients with intermediate-grade NHL or HD, and may be comparable to some previously used regimens including TBI-based regimens.