Previous reports of prolonged jaundice in cystic fibrosis have not described operative and histopathological findings in the liver and biliary tree. In the two cases reported here, obstructive jaundice in the neonatal period was associated with anatomical evidence of intra- or extrahepatic biliary obstruction. Hepatoportoenterostomy, a surgical procedure that is not without complications, was performed on one of the patients for biliary atresia before the diagnosis of cystic fibrosis was suspected. Prolonged obstructive jaundice may be an early manifestation of cystic fibrosis and may resolve without operative management. A sweat test should be performed on all patients with prolonged obstructive neonatal jaundice to rule out cystic fibrosis.