All patients receiving autografts for acute leukaemia in remission between 1 January 1981 and 31 December 1996 and reported to the European Group for Blood and Marrow Transplantation and had a relapse, were included. The patients underwent an allograft (n = 90, group A), were treated with chemotherapy (n = 2584, group B) or received a second autograft (n = 74, group C). The 2-year survival after relapse was 32 +/- 5%, 11 +/- 1% and 42 +/- 6% in groups A, B and C, respectively. In group A, those with an HLA-A, -B and -DR compatible related or unrelated donor had a 2-year survival of 37 +/- 7% compared to 13 +/- 8% for those receiving a graft from an HLA mismatched donor (n = 20). The following factors were associated with better survival in multivariate analyses: an interval from first autograft to relapse >5 months (P < 0.00001), a first autograft performed later than 1991 (P < 0.00001), patient age below 26 years (median, P < 0.002), group B vs HLA mismatches from group A (P = 0.002), group C vs group B (P < 0.005), patients who were not treated with total body irradiation at first autograft (P < 0.02) and patients in first remission at first autograft (P = 0.02). To conclude, the poor outcome in these patients was improved if a second autograft was feasible (P < 0.005), or if an HLA-matched allograft was performed (NS). Bone Marrow Transplantation (2000).