THE PURPOSE of this communication is to report a case of congenital cystic dilatation of the common bile duct which was treated successfully by a Roux en Y anastomosis between the cystic dilatation and the jejunum. Apparently this procedure has not been reported heretofore as a method of establishing a satisfactory connection between the biliary and the gastrointestinal tracts in the treatment of this rare lesion1. CASE REPORT F. M., a 30 year old white man, an office worker, was admitted to Mercy Hospital on Feb. 3, 1946 because of epigastric discomfort and nausea. Much of his history has been obtained from relatives since his operation and discloses that as an infant he had episodes of gastric disturbances which became more frequent at about the age of 5. It was remembered that he was always underweight and had a sallow complexion. Beginning at the age of 6 and recurring