The aims of the study were to determine the nature of the procoagulant activity present in the ascitic fluid and the means to inhibit the thrombotic complications appearing after peritoneovenous shunting. In a prospective study, 10 ascitic fluids (5 exsudates, 5 transsudates) were studied. The procoagulant activity was defined as the capacity of ascitic fluid to shorten the recalcification time of a control plasma.Our results showed :1. All the ascitic fluids exhibited a procoagulant activity.2. The procoagulant activity of the cellular fraction was related to the presence of platelet factor 3 (PF3) and polymorphonuclear elastase and may be inhibited by the combination of inhibitors of PF3 (phospholipase A inhibitor calbio-chem) and elastase antibody.3. The procoagulant activity of the free cellular fraction was related to the presence of thrombin, factor Xa, PF3 and tissular thromboplastin, and may be inhibited by a combination of Antithrombin III, phospholipase A and Diisopropyl-fluorophosphate.Conclusion :1. The important procoagulant activity of ascitic fluid is present in both cellular and acellular fractions and is related to the presence of different coagulation activators (PF3, elastase, Xa, thrombin, tissular thromboplastin).2. The administration of a combination of AT III and phospholipase A in the ascitic fluid before the contact with the whole blood allows to inhibit the procoagulant activity of ascitic fluid and could prevent the thrombotic complications appearing after peritoneovenous shunt.