The Fondazione Lorenzini has been sponsoring Postgraduate Courses for physicians and specialists, in Italy, since 1970. Its aim, as an institution, has been that of promoting post graduate medical education. In these years, recent advances in a wide range of medical fields have been discussed by distinguished experts from many countries throughout the world. Courses dealing with methodo logies and technical problems have been designed to include practical demonstrations of the various methods and techniques in the relevant fields. The Postgraduate Course on Platelets and Thrombosis: Methods of Study was held in Milan, at the Fondazione Lorenzini, from February 24th to 26th, 1972. This volume contains the edited and somewhat extended papers presented at the Course, which was sponsored and organized by the Italian Society for the Study of Atherosclerosis. The special contribution of the present volume is that of gathering a large amount of up-to-date information on the formidable problem of the methods used for testing platelet function in thrombosis.