Platelet transfusion has become an integral part of the management of disseminated malignant disease and its role in preventing or controlling haemorrhage due to thrombocytopenia is now without dispute. This monograph contains articles presented at an Inter- national Symposium on Platelet Transfusion held in London in July 1978. It is hoped that they provide an up- to-date review of the preparation and laboratory function of platelet concentrates in addition to practical advice towards developing an intelligent approach towards their administration. T.A. Lister j.S. Malpas 9 1 Platelet Collection and Quality Control D. Huestis In this chapter I would like to discuss platelet collection tcchniqlll" and q ualit \7 control; the more clinical aspects will be covered by otl)(, l contributors. In the first place it would be prekrable to l()()k .11 platelets from the point ofvin" of the physician lIsingthern - whatlw needs to know so that his usc of platelets will he intelligent and directed by bac kground knowledge of vvhere platelets are found. hcm they arc halYested and stored. and the clinical realities of platekt t ranslilsion. The platelets we transfuse tomorrow walk the streets today. Intelligent donor recruitment and public information carnpaigm about blood donation, and about new systems of blood donation that arc not yet familiar to the general public, need to be broadcast and developed, but are not really a subject of discussion for this meeting. HISTORICAL REVIEW I shall start with an historical perspective on the evolution of platelet transfusion.