The textbook "Platelets and Megakaryocytes" offers a comprehensive examination of the biological cell types platelets and megakaryocytes, which are crucial for hemostasis. It highlights the role of platelets in blood coagulation and the challenges associated with their excessive activation, which can lead to morbidity and mortality in Western societies. The book aims to integrate existing and newly developed techniques to enhance the understanding of platelet activation under physiological and pathophysiological conditions. It consists of two volumes, with the first volume addressing functional tests, while the second volume focuses on signaling techniques and post-genomic methods. The detailed analysis of megakaryocyte biology is considered essential for the development of targeted gene approaches for platelets. The various chapters provide valuable perspectives and methods for researchers in this field.