Between September 1986 and June 1998, 99 patients with relapsed or refractory IGL received intensified preparative therapy and underwent autologous transplantation at a single institution. Two intensified preparative regimens were used: cyclophosphamide, etoposide, total body irradiation (CY-VP-TBI) (n = 66) and cyclophosphamide, BCNU, etoposide (CBV) (n = 33). As clinical features and results were not different for the two preparative regimens, results were combined. For all patients undergoing autologous transplantation, 5-year actuarial overall survival (OS) was 34% +/- 6%; 5-year event-free survival (EFS) was 26% +/- 5%. For patients who responded to primary therapy, salvage therapy, or both, OS was 42% +/- 7%; for non-responders to prior therapy, OS was 14% +/- 7%, P < 0.025. OS was better among patients responding to salvage therapy (50% +/- 9%), than among patients who had a complete response to initial therapy, but failed to respond or were untested/unevaluable with respect to salvage therapy (26% +/- 10%; P < 0.025). On multivariate analysis, response to salvage therapy was associated with survival following autologous transplantation (P < 0. 005). Treatment related mortality was 9% overall and only 6% after G-CSF and GM-CSF were introduced into routine clinical practice. High-intensity preparative therapy is highly effective, with acceptable treatment-related mortality, in patients with IGL who have responded to induction therapy, salvage therapy, or both. The best responses are observed in patients responding to salvage therapy. Randomized prospective studies will be needed to further define the role of intensified preparative regimens. Bone Marrow Transplantation (2000) 25, 257-262.