An intraductal papillary mucinous neoplasm (IPMN) is now a well-recognized disease entity. In general, the prognosis of IPMN is much more favorable than that of pancreatic ductal adenocarcinoma (PDAC). However, IPMN has a broad biological spectrum and it sometimes progresses, slowly showing neoplastic transformations. International consensus guidelines have been recently proposed for the management of IPMN. While they significantly contribute to appropriate management of IPMN, various issues including the natural history and malignant potential of IPMN are not fully elucidated. This review focuses on the malignant potential, including the postoperative recurrence of IPMN, coincidence of IPMN with PDAC, and extrapancreatic malignancy that may affect the long-term survival of the patients rather than IPMN itself.