BACKGROUND: Platelet (PLT) doses of 1.1 × 1011, 2.2 × 1011, and 4.4 × 1011/m2 body surface area are equally effective in preventing bleeding. These different dose strategies involve different numbers of transfusions. We conducted a cost analysis of three separate PLT dose therapies. STUDY DESIGN AND METHODS: A process map of preparation and administration of a PLT transfusion identified 46 steps (23 steps in the blood bank and 23 steps on the care unit). Time studies were conducted for these 46 steps. Supply costs and personnel costs were estimated based on time studies. We conducted a cost analysis of three separate treatment regimes involving 16 transfusions per patient for the low-dose, 12 transfusions for medium-dose, and eight transfusions for high-dose regimes. RESULTS: The time and the cost of the transfusion process for the blood bank were 32.41 minutes and $21.93 per unit, and for the patient care unit, 58.36 minutes and $57.71 per unit. The total cost for a course of PLT therapy per patient ranged from $4503.77 to $7014.59 for three different PLT doses. For a simulated bone marrow transplantation unit with 259 patients annually, there would be approximately a $700,000 difference among the clinically equivalent low-, medium-, and high-dose treatment options. CONCLUSIONS: The overall cost of transfusion therapy is more influenced by the cost of the product than the cost of providing the transfusion. Depending on the cost adjustment by the supplier for different doses of PLTs, a low-dose transfusion strategy can be less costly.