We herein present the case of an intraductal papillary mucinous tumor of the pancreas resected by a gastric tube-preserving pancreatoduodenectomy in a patient who underwent an esophagectomy and reconstruction using the gastric tube. To preserve the gastric tube, the gastroduodenal artery and right gastroepiploic vein must be successfully skeletonized and preserved. In the present case, the vascular anatomy was clarified not only two-dimensionally with the use of selective abdominal angiography, but also three-dimensionally with the use of helical computed tomography. After precisely identifying the location of the tumor in relation of the blood vessels, it was confirmed that a gastric tube-preserving pancreatoduodenectomy was feasible. A detailed analysis of the vascular anatomy should be carried out by helical computed tomography preoperatively. When the radicality of tumor resection is not compromised, a gastric tube-preserving pancreatoduodenectomy can be recommended, due to the fact that it is considered to be less invasive.