The persistence of jaundice beyond the first 2 weeks of life require further investigation and this can be determined if the conjugated bilirubin levels are greater than 1.5 mg/dL or greater than 20% of the total bilirubin level. There is a diverse differential diagnosis for the cause of neonatal cholestasis due to hepatobiliary disease including biliary atresia, which eventually leads to liver cirrhosis if uncorrected before 60~80 days of life. Long-established initial studies include abdominal ultrasonography, hepatobiliary scintigraphy and liver biopsy, but better diagnostic methods are needed. Promising new options are described including MRCP (magnetic resonance cholangiography), ERCP (endoscopic retrograde cholangiography), and PCC (percutaneous cholecysto-cholangiography). Though no single test can differentiate biliary atresia from other neonatal cholestasis with confidence, a combination of diagnostic methods is usually consistently beneficial. By excluding biliary atresia as early as possible, the risk of unnecessary explolaparotomy with intraoperative cholangiography is decreased. Further evaluation would be required for the diagnosis of neonatal cholestasis after excluding biliary atresia.