PURPOSE: The object of this study is to evaluate the clinical findings and the outcome of choledochal cysts (CC) in children. METHODS: All cases of CC that underwent operation between 1983 and 2006 were studied retrospectively. We evaluated the symptoms and signs, types, anomalous pancreaticobiliary union (APBDU) and complications of CC. RESULTS: Forty-five children were included. The common age range was from 1 year to 5 years. The male to female ratio was 1 to 3. The most common symptom was abdominal pain (71.1%). The main methods of diagnosis were US and CT. According to Todani's classification, type I (60%) and type IV (35.6%) were most common types. APBDU was confirmed in 21 cases. B-P type (13 cases) was more common than P-B type (8 cases). Three among four patients with pancreatitis had a stone or protein plug in the common channel. Cyst excision with hepaticojejunostomy was performed in most cases. The overall morbidity and mortality were 8% and 0%, respectively. There were no problems, such as cholangitis, biliary stone and biliary cancer during the follow up. Intrahepatic duct dilatations of type IVa disappeared in the postoperative follow up study, except one. CONCLUSION: The outcome of cyst excision with hepaticojejunostomy was excellent. As for CC accompanied with the pancreatitis, the presence of stone or protein plug in the common channel needs to be examined. It is hard to precisely interpret that intrahepatic duct dilatation in type IVa normalize during the postoperative follow up until more evidence is accumulated.