Cystic diseases of the biliary tract encompass a complex group of congenital disorders. Some of the disorders, such as Caroli disease and the hepatobiliary cysts of autosomal-dominant polycystic kidney disease, share common embryologic origins, whereas others, such as choledochal cysts, biliary diverticula, and choledochoceles, have unclear origins. This article reviews the embryologic, clinical, pathologic, and imaging features of biliary cystic disease.