Despite the current emphasis in transfusion medicine on regulatory compliance and cost containment, there is continuing activity in quality improvement of blood products. Quality can be assessed by measuring both benefit and risk. High quality products are those in which the benefit is maximized and the risk minimized. Risk, in the context of platelet transfusions, is minimized by reducing infectious agents, sources of allergic reactions, and other factors likely to cause adverse reactions in recipients. Benefit can be better described as potency. Potency is the ability to produce a desired effect. For platelet concentrates, potency has both quantitative [platelet yield] and qualitative [platelet viability, survival, and function] components. There are many activities which may influence the potency of the final transfused platelet product and these are summarized in Figure 1. It is helpful to review each step in order to assess the potential impact on the potency of the final transfused product.