To date, conventional U.G.I. series and hypotonic duodenography play key role in the diagnosis of carcinoma of pancreas. However, findings in the these studies are nonspecific for carcinoma of pancreas, because these studies are indirect visualization of neighboring hollow viscus. Author reviewed 29 cases of operatively confirmed carcinoma of pancreas retrospectively, and obtained significant results. Most freqeunt and reliable finding in the diagnosis of carcinoma of pancreas is compression defect in the posterior wall of stomach with or without widening of retrogastric space. As contrary to the fact that most rdiologists considered C-loop widening to be sine qua non, it is demonstrated in only 44%. Instead, C-loop was collapased in 41% of cases. This is considered to be due to extensive involvement of duodenum and localized abhesive process in the vicinity of carcinoma. In fact, C-loop widening is not characteristic finding of carcinoma of pancreas. One must obserbed his own radiographs meticulously and conclusion should be made after consideration of every possibilities in the diagnosis of carcinoma of pancreas.