In this paper the impact of hemapheresis technology on 238 allogeneic bone marrow transplants performed in Pescara from 1982 through 1993 is described. Granulocyte transfusions were limited to patients with neutrophil level < 0.2 x 10(9)/L. An average of 4 units of packed red blood cells were required to maintain adequate hemoglobin levels. Patients with major ABO incompatibility showed an increased requirement of red blood cell support as compared to patients ABO-matched and ABO minor mismatched. For platelet support single-donor platelets collected on a blood-cell separator were given. A total of 1548 platelet transfusions were examined. The median number of platelet transfusions for each patient was 5. Platelet refractoriness occurred in 44% of patients. The hemorrhage related mortality was 0.9%. The advancement made in the field of hemapheresis technology, as well as the improved transplant technique, have contributed to increase the post-transplant survival from 17% in the early experience (1976-1982) to 88% in the recent years (1992-1993).