Choledochal cyst, although more common in females than in males, has only rarely been encountered in association with pregnancy. A 29-year-old nulliparous woman at 32nd week gestation was diagnosed as acute pancreatitis with co-existing type l choledochal cyst. Resection of the choledochal cyst was performed and a Roux-en-Y hepatico-jeunostomy was carried out to provide biliary drainage. Although the preferred management of a choledochal cyst is excision and Roux-en Y reconstruction, this may have to be deferred until after delivery, depending on gestational age, because of the risk of fetal mortality and maternal morbidity that is associated with this procedure.