This report presents the analysis of leukemic relapse of 52 patients who received allogeneic bone marrow transplantation between July 1984 and May 1990. Conditioning regimen consisted of TBI + CY and GVHD prophylaxis consisted of cyclosporin-A and methotrexate. The relapse ratios of chronic myelogenous leukemia (CML) (21 in chronic phase, 1 in accelerated phase, 1 in blastic crisis), acute nonlymphocytic leukemia (ANLL) (all 17 in 1st CR), acute lymphocytic leukemia (ALL) (all 12 in 1st CR) were 13%, 18%, 25%, respectively, and 3 year disease free survival (DFS) was as follows, CML 68%, ANLL 72%, ALL 49%. Regarding acute GVHD grading and chronic GVHD presence, 3 year DFS was as follows, acute GVHD 0 degree: 59%, I degree: 78%, II degree-IV degree: 53%, chronic GVHD (+): 82% GVHD (-): 77%. In our center leukemic relapse has been the major cause of death after BMT since 1984. Among 9 relapsed cases, one recurred more than 3 years after BMT, and another one got recurrent leukemia of donor origin.