Purpose: Choledochal cysts are congenital bile duct anomalies that were first discussed by Vater and Ezler in 1723. The incidence is uncommon in Western Countries ranging from 1 case in 150,000 to 1 case in 2 million live births however; the prevalence in Asia nears 1 case in 1000. More than 60% present in the first year of life and are more common in females.1,2 The underlying etiology involves the anomalous development of the pancreaticobiliary duct union which results in a long common non-dilated channel. The absence of a sphincter around the union results in reflux of pancreatic juice into the biliary tree and is the presumed etiology of the eventual development of cholangiocarcinoma later in life. Surgery involving total cyst excision with biliary-enteric anastomosis is often recommended with the goal of avoiding cholangiocarcinoma. Patients 20 to 30 years old have a cancer risk of 2.3%; whereas in patients 70 to 80 years of age, this risk may rise to 75%.3,4 Intrahepatic biliary tract carcinomas rarely arise after surgery; however, the ducts left behind hold the potential for cancer development. Shimamura et al reported only 8 cases in the English and Japanese literature of intrahepatic cholangiocarcinomas (IHCC) developing following resection of a choledochal cyst and was generally less than 10 years following surgery.5 We present a case report of IHCC found 60 years after choledochoduodenostomy surgical bypass at the age of 5 months for a type 1 congenital choledochal cyst. Our patient seems unique in that the cholangiocarcinoma developed after 60 years in the intrahepatic ducts and not in the bypassed but retained choledochal cyst. In this case, intrahepatic ductal exposure to pancreatic juice would have been only intra-utero and for the first 5 months of life, raising some doubts as to the universal mechanism of carcinogenesis in type 1 disease. This case and the rare development of intrahepatic cholangiocarcinomas reported post-resected of type 1 cysts should be kept in mind in following these patients. Whether routine surveillance can be recommended of post-resection patients by endoscopy for cytology or EUS would require a larger experience.