Intraductal papillary mucinous neoplasm(IPMN)of the pancreas often presents with multifocal lesions. Complete resection without residual skip lesions is essential for complete eradication of the disease. We experienced a case of IPMC in which intraoperative pancreatoscopy was used to determine the surgical margin. Intraoperative pancreatoscopy is a useful and easy method to evaluate the remnant duct and exclude residual tumor. A cystic lesion was incidentally detected in the pancreatic head of a 78-year-old man. Ultrasonography, abdominal computed tomography, magnetic resonance imaging, and endoscopic ultrasound revealed enhancing mural nodules in the pancreatic head and dilation of the entire main pancreatic duct. We performed pancreaticoduodenectomy for mixed IPMN. Intraoperative pancreatoscopy, which was performed to rule out skip lesions, showed no mucosal abnormalities in the remnant duct. The pathological diagnosis was non-invasive intraductal papillary-mucinous carcinoma(IPMC). No signs of recurrence were seen for 6 postoperative months.