From 1977 until June 1987, 139 patients with leukemia underwent allogeneic bone marrow transplantation at Huddinge Hospital. Among recipients of HLA identical bone marrow the survival plateau for 30 patients with acute myeloid leukemia in first remission was 71% from 3 to 7 years. Children (n = 11) had a survival of 100% compared with 52% (n = 19) in adults (p = 0.01). Among patients with acute lymphoblastic leukemia in first remission (n = 15) the actuarial 5-year survival was 73% compared with 31% for those (n = 25) in second to fourth remissions. The probability of relapse in these two groups was 9% and 45% respectively (p less than 0.05). Patients with chronic myeloid leukemia in first chronic phase (n = 27) had a survival plateau from 1 to 6 years of 65%. In Cox's multivariate regression analysis, improved survival was associated with grade 0-I acute graft-versus-host disease (GVHD) (p less than 0.0001), HLA-matched siblings (p less than 0.001), recipient age less than 17 years (p = 0.02), first remission and first chronic phase (p = 0.03), cytomegalovirus (CMV) seronegative recipients (p = 0.04) and absence of symptomatic CMV infection (p = 0.04). A decreased risk of relapse was seen in patients with first remission or first chronic phase (p less than 0.001) and in patients with asymptomatic CMV infection (p = 0.03). In multivariate analysis the p values were 0.002 and 0.09 for these two groups respectively. In these patients acute GVHD was the major obstacle to successful outcome.