OBJECTIVE To investigate the prognostic relevance of hepatobiliary scintigraphy (HBS) in newborns suffering from biliary atresia (BA) for establishing the primary diagnosis and in the postoperative follow-up after portoenterostomy (Kasai). METHODS Twenty newborns with direct hyperbilirubinemia and 6 children after operative treatment of BA (Kasai) underwent HBS with Tc-99m-DEIDA. In patients without intestinal drainage, hepatocellular extraction was estimated visually and calculated semiquantitatively by means of liver/heart-ratio 5 min p.i. RESULTS 10/20 patients with hyperbilirubinemia did not display biliary drainage; 6 had BA, 3 intrahepatic hypoplasia, and one showed a bile plug syndrome. 4/6 with BA but none of the 4 children with diagnoses other than BA presented with a good extraction. All of the 4 children with BA, who had either pre- or postoperatively a bad extraction, needed liver transplantation due to liver failure. Both of the two newborns with BA and favourable outcome after Kasai had a good extraction in the preoperative HBS and demonstrated good intestinal drainage in the postoperative scan. CONCLUSIONS HBS rules out BA with high accuracy by demonstrating drainage of bile into the intestine. In newborns without drainage a good extraction favours the diagnosis of BA. In newborns with BA a bad extraction seems to indicate a poor postoperative prognosis after Kasai operation. HBS might therefore help to select those children who will not benefit from portoenterostomy. Postoperatively, HBS can easily and quickly confirm the successful hepatobiliary anastomosis by demonstrating biliary drainage into the intestine.