Forty-five pancreatoduodenectomies had been performed in our hospital from 1981 to 1994, of which 35 cases were diagnosed as carcinomas of Vater’s ampulla or pancreatic head, and 10 (cases) as benign lesions. Through analysis of misdiagnosed cases, the authors emphasize that it is important to take correct history of jaundiced patients in detail according to the character of the jaundice and associated symptoms before any operation done. Secondly, all clinical materials must be thoroughly collected and special examinations for diagnosis should be chosen scientifically to avoid relying only on one sort of examination result as diagnostic standard. Thirdly, during operation the area of pancreatic head should be explored carefully and any lesions in doubt should be examined pathologically by puncture biopsy and frozen section to avoid misdiagnosis and thus performing pancreatoduodenectomy.