The paper is concerned with analysis of CT-investigation of 150 patients with diseases of the biliopancreatoduodenal area, whose diagnosis was verified histologically or by clinical observation over time, using other methods, (USI, RCPG, etc.). The authors have arrived at a conclusion that for increasing the informative value of CT one should use various methods of a contrast study of the duodenum and biliary tract, electron reconstruction of CT images in different projections. They have pointed out the most significant differential-diagnostic CT signs, proposed a table to facilitate the identification of causes and a level of obturation of the bile ducts, the table playing an important role in a choice of adequate therapy.