The inadvertent transmission of AIDS virus through contaminated whole blood has shaken the viability of the American voluntary blood supply system. For the first time since the voluntary donor system replaced the commercial blood system, there are widespread doubts about the ability of blood suppliers to meet the nation's increasing health care demands. This paper presents a framework for analyzing blood collection. First, we critique the existing literature on blood collection, arguing that its focus on donor motivation is difficult to integrate with policy analysis. We then present a specific model of the individual's decision to donate blood as a comparison of the costs and benefits of donating. The current system of collecting whole blood relies on donors receiving only altruistic benefits. We explore the limits of this approach to dealing with the quantity and quality problems presented by the AIDS virus. Alternative approaches to blood collection which allow personal benefitssuch as donor designation or monetary paymentsmay be necessary to supply the nation's blood demands in the future.