We report a case of a 33-year old man who presented with symptoms and signs of an acute biliary tract obstruction with jaundice and abdominal pain. Diagnostic imaging studies revealed a biliary stricture of the hepatic confluence, and a mass at the hepatic hilum which obstructed the extrahepatic bile duct from the outside. At laparotomy, there was 3-cm-size nodule at the hilum which presented with a rubbery consistency. We performed extrahepatic bile duct resection and right and left hepaticojejunostomy. Histological examination of the resected specimen revealed follicular lymphoma, which consisted of medium cleaved follicle-like cells, grade 1 of 3 according to the revised European-American classification of lymphoid neoplasms proposed by International Lymphoma Study Group. Postoperative follow-up of more than 1 year has been completely uneventful, without any symptoms or signs of disease recurrence. This is the second case report of follicular lymphoma of the extrahepatic bile duct.