In recent years, the disease concept of intraductal papillary neoplasm of the bile duct (IPNB) has been attracting attention as a biliary lesion that is morphologically similar to intraductal papillary mucinous neoplasm (IPMN), which is considered to be a counterpart of IPMN. However, there are few reports on IPNB, and a consensus regarding the features of this disease is thus lacking. We experienced an extremely rare case of IPNB occurring in the bile duct at the duodenal papilla, which is a tumor presentation that has not previously been reported. Herein, we report this interesting case and discuss the possible association between IPMN and IPNB.