Platelet Activating Factor (PAF) is a naturally occurring substance with potent biological effects which have a broad significant role in the activation of various inflammatory cells. It therefore contributes to a number of serious clinical conditions including anaphylaxis, allergic and inflammatory diseases (eg. asthma, rhinitis, thrombosis). This book brings together leading investigators in the field to present their latest research directed towards the biosynthesis of PAF, its cellular origins, PAF induced cellular and tissue responses, pathophysiological responses and, most important, to finding effective antagonistic drugs to control this inflammatory mediator.