Pancreas-preserving duodenectomy is indicated for select patients with a duodenal tumor in the second portion. In this procedure, identification and closure of the accessory pancreatic duct is important to prevent postoperative pancreatic fistula. A 63-y-old man was diagnosed with duodenal mucosal carcinoma in the second portion, with invasion of the major ampullary. We performed pancreas-preserving duodenectomy. Intraoperatively, indocyanine green-fluorescent imaging identified the accessory pancreatic duct clearly and it was successfully closed. Postoperative pancreatic fistula did not occur. Indocyanine green-fluorescent imaging is effective in identifying the accessory pancreatic duct in pancreas-preserving duodenectomy.