Two patients with intraductal papillary-mucinous adenoma of the pancreas were successfully treated by ductal branch-oriented minimal pancreatectomy. We propose this novel less invasive ductal branch-oriented pancreatectomy, as indicated for benign ductal ectasia of the pancreas. The cystically dilated branch duct is identified by intraoperative ultrasonography, intraoperative balloon pancreatography, and injection of indigocarmine into the cyst. The cystically dilated branch is resected from the surrounding pancreas together with minimal removal of the pancreatic parenchyma. The communicating duct and cutting margins are tightly ligated to prevent pancreatic juice leakage and fistula. A drainage tube is placed in the main pancreatic duct whenever possible. Histopathologic examination of the transected branch duct is necessary to check for mucosal extension of dysplastic epithelium. This ductal branch-oriented minimal pancreatectomy is the least invasive pancreatectomy and a suitable operation for branch-type ductal ectasia of the pancreas, which is usually benign.