Allogeneic bone marrow transplantation for advanced hematologic cancer is associated with a high risk of early treatment-related morbidity and mortality. To determine the short-term benefits of allogeneic blood stem cell transplants when compared to bone marrow transplants, we reviewed outcomes of 74 adults with advanced hematologic cancer transplanted from HLA-matched related donors after conditioning with thiotepa, busulfan and cyclophosphamide. There were three cohorts: group 1 received bone marrow transplants with cyclosporine (CsA) and methotrexate (MTX) for GVHD prophylaxis; group 2 received bone marrow transplants with CsA and methylprednisolone (MP); and group 3 received blood stem cells with CsA and MP. All patients received filgrastim post-transplant. Median times (range) to neutrophils > or = 0.5 x 10(9)/l were 17 (8-30), 9 (8-16) and 10 (8-13) days post-transplant, and to platelets > or = 20 x 10(9)/l were 28 (14-100+), 19 (13-100+) and 14 (9-86) days post-transplant for groups 1, 2 and 3, respectively (P < 0.05 only for group 1 vs group 3 for both outcomes). Blood stem cell recipients had the least regimen-related toxicity, fewest early deaths and earliest discharge. There was no significant difference in acute GVHD between the three groups. One hundred and eighty-day survivals (95% CI) were 53% (35-72%), 32% (10-53%), and 68% (49-87%) for groups 1, 2 and 3, respectively (P < 0.05 only for group 2 vs group 3). For allogeneic transplantation, use of blood stem cell grafts has substantial advantages over marrow grafts.