Choledochal cyst is a rare congenital abnormality of the bile duct and usually occurs in young ages. We presented a 19 year-old girl who suffered from abdominal pain, fever and jaundice, and was subsequently diagnosed with Todani type IA choledochal cyst. Surgery with choledochal resection, mucosectomy of distal common bile duct, cholecystectomy, and Roux-en-Y hepaticojejunostomy was performed. She enjoyed full recovery after the operation. Early diagnosis of choledochal cyst is important due to its potential for malignant transformation, and thus surgical intervention for total cystic excision is recommended.