As one of the various causes of mucin-producing tumor of pancreas, villous adenoma("papillo- matosis) is exceedingly rare. Because abundant mucin impairs obtaining precise pancreatography, the tumor shows a superficial spread, and histologic diagnosis is seldom made preoperatively, pancreatoscopy is useful to visualize the intraductal extent and to diagnose histologically. There has been no report on the mucin-producing papillomatosis in Korea, and only one histologically diagnosed case by peroral pancreatoscopic biopsy has been reported throughout the world. We report a 58-year old male whose duodenoscopy revealed the characteristic findings of papilla and ERP showed a l.5 cm nodular mass at the pancreas head. Peroral pancreatoscopy using 4.1 mm choledochoscope revealed a papillary tumor in main pancreatic duct, and numerous tiny finger-like projections were also noted around the above lesion. Pancreatoscopic biopsy revealed villous adenoma with low grade dysplasia. As the patient refused the operation, endoscopic retrograde pancreatic drainage(plastic, 10 Fr, 7 cm) was performed