The features of clinical course, the frequency and the pattern of gastrointestinal bleedings after diverse abdominal operations were studied over a period of time from 1993 to 2006. Postoperative gastrointestinal bleedings were observed at 503 patients. The frequency of postoperative gastrointestinal bleedings amounted 0.5% after operations on account of purulent diseases with different localization, 0.6% after abdominal and cardiovascular operations, 0.8% after lung operations, 1.5% after operations on the account of burn disease, 6.1% after hepatopancreatobiliary operations. In accordance with the stages of postoperative period, distinctions in endoscopic picture and the tactics of treatment early and late bleedings were distinguished during the investigation. It has been established, that blood supply disturbance in portal vein, manifested by transient portal hypertension is, one of the most important pathogenetic factors of development of bleeding after hepatopancreatobiliary operations along with acute erosive (ulcerous) affection, caused by stress or trauma, and multiple organ failure. The features of clinical course of postoperative bleedings were studied in different groups of surgical patients. The comparative evaluation of efficacy of endoscopic methods of hemostasis (injection,various endoclips, hydrothermocoagulation, argon-plasma coagulation) was carried out. It was shown that the application of new methods of endoscopic sanation and investigation of the upper gastrointestinal tract had resulted in increase of frequency of exposure of gastrointestinal bleeding source from 69.8% to 88.4% at primary urgent esophagogastroscopy. The efficacy of hemostasis at postoperative gastrointestinal bleeding raised from 70.3% to 92.4%.