Purpose. To study the possibilities of CT perfusion (CTP) in detecting periampullary tumors depending on the anatomical localization, to compare the diagnostic efficiency with the standard CT protocol. Materials and methods. CT scan of the abdominal organs according to the standard protocol and CTP were performed in 229 patients with periampullary tumors. Results. In adenocarcinoma of the pancreas, compared with adenocarcinoma of the major duodenal papilla, BF, BV, MSI (p<0,005) were statistically significantly lower, there were no differences in MTT, TTP, and PS (p>0,005). In distal cholangiocarcinoma, compared with adenocarcinomas of the pancreas and the major duodenal papilla (MDP), the BF, BV and MSI values were statistically significantly higher, the TTP values were lower (p<0,005), there were no differences in the MTT and PS values (p>0,005). Conclusion. CT perfusion is a highly informative method for detecting and determining the anatomical affiliation of periampullary tumors with a sensitivity of 98,7%, a specificity of 98%, and a diagnostic accuracy of 98,4%.