OBJECTIVE The authors reviewed their experience with resected IPMT (intraductal papillary-mucinous tumor) of the pancreas to clarify the characteristics and prognosis of this neoplasm. METHODS Between 1983 and 1998, 30 consecutive patients with IPMT underwent operations at our institution. Their clinicopathological features and postoperative long-term outcomes were analyzed retrospectively. RESULTS There were 22 males and 8 females, with a mean age of 64 years. Operations performed were duodenum-preserving pancreatic head resection in 12 patients, distal pancreatectomy in 8, segmental pancreatectomy in 6, conventional pancreaticoduodenectomy in 4. Malignancy was found in 10 of 30 (33%). Factors significantly associated with malignancy were tumor size or presence in main pancreatic duct. In 30 resected patients after a mean follow-up of 60 months, tumor recurrence had occurred in 2 cases of invasive carcinoma that infiltrated into the extrapancreatic organ. The overall actuarial 5-year and 10-year survival was 83% and 62%, respectively. CONCLUSIONS IPMT has a favorable prognosis after adequate resection. Despite slow growth, IPMT has an obvious malignant potential and a poor prognosis when invasive carcinoma has developed. Early recognition and pancreatectomy is the mainstay of treatment for IPMT.