Few pathologie phenomena, as shock, can originate from so many causes and involve so many complex physiologie mechanisms: The complexity of the phenomenon, thus, has resulted in extensive study and raised many uncertainties. Different conditions, such as hemorrhage, trauma, burns, bacterial infection, and anaphylaxis, can cause a shock state which initiates a chain of biochemical events that tends to maintain the shock. Recent progress in bio­ chemistry, physiology, and pharmacology has tended to clarify this chain of events, and elucidate the possible trigger mechanism. Besides the hormonal and catecholamine involvement, the possible intervention of various protease and lysosomal enzyme septems and kinin release introduces new elements into the characteristic mosaic of the shock state. This International Symposium, organized at Lake Corno by the Italian Society of Clinical Pharmacology and the International Society of Biochemical Pharmacology, is another in aseries of symposia under the joint auspices of the School of Pharmacy, State University of New York at Buffalo, and the Institute of Pharma­ cology, University of Milan, Italy. The Symposium has gathered together eminent scientists from such varied disciplines as surgery and pharmacology, internal medicine and biochemistry, physiology and pathology, all focusing on the question of shock. The many researchers in these specialities had the possibility of meeting and discussing together in a multidisciplinary fashion the many theories and experiences associated with this problem.