Cholescintigraphy using 99mTc-diethyl-, 99mTc-diisopropyl-, 99mTc-iodo-diethyl- and 99mTc-bro-motrimethyl-IDA was performed in 22 newborns and infants with direct hyperbilirubinaemia. Retrospective evaluation of 99mTc-diethyl- and 99mTc-diisopropyl-IDA (n = 18) showed an efficiency of 66% in the differentiation between extrahepatic biliary atresia and neonatal intrahepatic diseases if the hepatocyte-clearance index and transit time were taken into consideration; the sensitivity of detecting extrahepatic biliary atresia was 100%. Cholestyramine treatment (n = 9) did not increase the efficiency of the test. Efficiency was markedly reduced when the serum direct bilirubin level was above 5.5 mg/dl (94 mumol/l). The gall bladder was not visualized in 13 out of 18 examinations. The prospective and retrospective analysis of 99mTc-iodo-diethyl- and 99mTc-bromo-trimethyl-IDA revealed intrahepatic disease in all 6 infants with serum values up to 12.6 mg/dl (216 mumol/l) direct bilirubin; the gall bladder was not visualized in 4 out of 7 examinations.