Prognostic factors to identify patients with high-risk non-Hodgkin's lymphoma (NHL) have recently been developed. We retrospectively investigated the relation between prognostic factors and treatment outcome after autologous bone marrow transplantation (ABMT). From 1984 to 1994, 80 consecutive patients with NHL responding slowly to or relapsing after front-line therapy were treated with high-dose chemotherapy and ABMT. Prognostic factors at the time of diagnosis and of ABMT were related to clinical outcome after ABMT. The cumulative 5-year overall survival (OS) was 51%, progression-free survival (PFS) 41%, and relapse-free survival (RFS) 53%. Absence of B symptoms and intermediate-grade malignancy at first presentation of disease were independently related to prolonged OS (P = 0.02 and P < 0.01, respectively) and prolonged PFS (P = 0.005 and P = 0.01, respectively). At the time of ABMT, first PR or CR, normal LDH levels and tumour stage I + II were associated with prolonged OS (P = 0.0005, P = 0.03 and P = 0.004, respectively). A Coiffier index of 0 or 1, first PR or CR and no extranodal disease involvement were related to prolonged PFS (P = 0.0002, P = 0.005 and P = 0.07, respectively). Treatment-related deaths occurred in 10% of patients. Assessment of disease status, LDH level, tumour stage, extranodal disease involvement and Coiffier index at the time of ABMT is respectively efficient in predicting treatment outcome after ABMT.