Learning Objectives: After studying this article, the reader should be able to: 1. Define the role of platelets in hemostasis and wound healing. 2. Describe the technologies for platelet concentration and application. 3. Characterize the platelet concentration and growth factor components of platelet-rich plasma. 4. List the potential applications of platelet-rich plasma in plastic surgery and how it may be applied intraoperatively. 5. Discuss the limitations of the use of platelet-rich plasma and its potential complications.Summary: Healing of hard and soft tissue is mediated by a complex array of intracellular and extracellular events that are regulated by signaling proteins, a process that is, at present, incompletely understood. What is certain, however, is that platelets play a prominent if not deciding role. Controlled animal studies of soft and hard tissues have suggested that the application of autogenous platelet-rich plasma can enhance wound healing. The clinical use of platelet-rich plasma for a wide variety of applications has been reported; however, many reports are anecdotal and few include controls to definitively determine the role of platelet-rich plasma. The authors describe platelet biology and its role in wound healing; the preparation, characterization, and use of platelet-rich plasma; and those applications in plastic surgery for which it may be useful.Healing of hard and soft tissue is mediated by a complex array of intracellular and extracellular events that are regulated by signaling proteins, a process that is, at present, incompletely understood.1-5 What is certain, however, is that platelets play a prominent if not deciding role.3,6 Platelet activation in response to tissue damage and vascular exposure results in the formation of a platelet plug and blood clot to provide hemostasis and the secretion of biologically active proteins. These proteins, in turn, set the stage for tissue healing, which includes cellular chemotaxis, proliferation, and differentiation; removal of tissue debris; angiogenesis; and the laying down of extracellular matrix and regeneration of the appropriate type of tissue. 2-4,6 In vitro, there is a dose-response relationship between platelet concentration and the proliferation of human adult mesenchymal stem cells, the proliferation of fibroblasts, and the production of type I collagen.7,8 This suggests that the application of autogenous platelet-rich plasma can enhance wound healing, as has been demonstrated in controlled animal studies for both soft and hard tissues. 9,10