The authors present a 3-month-old patient with a congenital choledochal cyst, which was asymptomatic until treatment. On laparoscopy, a type I choledochal cyst was confirmed and excised laparoscopically. A Roux-en-Y anastomosis was constructed after exteriorization of the small bowel via the infraumbilical trocar incision. A laparoscopic end-to-side hepaticojejunostomy was carried out. The operation lasted 4(1/2) hours, without intraoperative problems. Oral food intake was started on day 2 and well tolerated with bile stained stools. Symptoms of bowel obstruction occurred on day 8. On minilaparotomy, the Roux-en-Y anastomosis was found to be adherent to the mesenterium of the colon, leading to obstruction. After mobilizing the loop, the postoperative course was uneventful. We conclude that laparoscopic resection of congenital choledochal cyst and choledochojejunostomy was feasible in the youngest patient operated on so far. However, adhesive small bowel obstruction can also occur, as after conventional operation, when the bowel is exteriorized for Roux-en-Y hepaticojejunostomy.