More and more refined laboratory investigations for differential diagnosis of neonatal direct hyperbilirubinemia have been developed, but not one of them is absolutely diagnostic. All of them take time and by the time the infant is referred to the surgeon it is often too late, as the prognosis for successful surgical correction becomes rapidly worse with increasing age. Most authorities have now agreed that in cases of extrahepatic biliary atresia cirrhosis has already well developed after the second month of life. The only virtually certain methods of diagnosis are direct inspection of the gall bladder, cholangiogram, and a sizeable liver biopsy. Our clinical experience has convinced us that laparoscopy with liver biospy and simultaneous cholangiography by transhepatic puncture of the gall bladder is the simplest, fastest and most certain method for diagnosis. It allows for early differentiation of direct hyperbilirubinemia in the neonatal age and should be carried out if the hyperbilirubinemia has persisted during the first month of life and before laboratory investigations are instituted.