The purpose of this study was to evaluate autologous bone marrow transplantation (ABMT) for low-grade non-Hodgkin's lymphoma (NHL). Between 1983 and 1994, 34 patients with non-transformed low-grade NHL received high-dose chemoradiotherapy plus stem cell rescue with marrow or peripheral blood. At transplantation (5-182 months (median 32) after diagnosis), 2 patients were in complete remission (CR), 21 in partial remission (PR) or minimal disease; 11 had bulky/resistant disease. Four patients died from transplant-related causes and 10 from lymphoma progression. After 40 months median follow-up, 20 survive between 3+ and 88+ months after ABMT. One-year survival is 81% (95% confidence interval, 65-96%) and 5-year survival 37% (14-60%). The probability of relapse at 1 and 2 years is 53% (34-72%) and 75% (54-96%), respectively. Twenty-nine patients were in CR following ABMT and 11 survive in continuous CR 3 to 54 months later. Disease-free survival at 1 and 2 years is 35% (19-52%) and 18% (2-31%). Resistant disease was the only factor significantly associated with poor overall (relative risk = 3.0, P = 0.04) and disease-free survival (RR = 5.4, P = 0.003), while resistant disease and high LDH were associated with increased relapse. ABMT yields a high CR rate for patients with progressive low-grade NHL, but relapse is frequent. Even longer follow-up is required to determine its effectiveness in extending survival of patients with pre-transplant responsive disease.