Objective The purpose of the study was to determine the impact of tumor location in patients with a replaced right hepatic artery (r-RHA) who undergo pancreaticoduodenectomy for pancreatic adenocarcinoma. Methods A retrospective analysis was performed of a cohort of 117 patients with T3 PA who underwent PD between 2001 and 2015. The patients were divided into two groups, one with an r-RHA (r-RHA(+) group) and the other without an r-RHA (r-RHA(-) group), and surgical outcomes, margin status, and survival were compared between the two groups by tumor location, the uncinate process and the dorsal pancreas. Results Twenty-six patients were found to have an r-RHA. Though there were no differences in the intraoperative variables, such as operative duration and blood loss, the incidence of complications, and the R1 resection rates and overall survival between the patients with and without an r-RHA, when tumor was located in the uncinate process, positive microscopic surgical margins were seen significantly more frequently in the r-RHA(+) group (40%) than in the r-RHA(-) group (15%) (p=0.048). Conclusions When tumor was located in the uncinate process, R1 resection rates increased in the patients with r-RHA who underwent pancreaticoduodenectomy for pancreatic adenocarcinoma. Based on the spreading patterns of carcinoma via the extrapancreatic nerve plexus, it might be better to consider en bloc resection of the r-RHA to improve the R0 resection rate in the patients with tumor located in the uncinate process when extrapancreatic nerve plexus invasion is strongly suspected.