Sixty-nine patients with a history of low-grade B-cell non-Hodgkin's lymphoma (NHL) in sensitive relapse or incomplete first remission underwent high-dose chemoradiotherapy and anti-B-cell monoclonal antibody (MoAb)-treated autologous bone marrow transplantation (ABMT). At ABMT, 51 patients had low-grade histology and 18 patients had a history of low-grade NHL that had undergone histologic transformation to a higher-grade NHL. Before ABMT, only 20 of the 51 low-grade patients and 10 of the 18 patients with transformed histologies were in complete remission. Moreover, at the time of marrow harvest, 24 of the low-grade and eight of the transformed histology patients had histologic evidence of lymphoma cells infiltrating the marrow. Following high-dose therapy, only one acute, in-hospital death was observed. There was no significant difference in the disease-free survival (DFS) between patients with low-grade and patients with transformed histologies. Among patients with low-grade NHL, the patients in complete remission before ABMT experienced significantly longer DFS than those in partial remission (P less than .05). This preliminary study suggests that some patients with relapsed low-grade NHL may experience prolonged DFS following high-dose ablative therapy.