BACKGROUND It is a globally challenging problem to differentially diagnose biliary atresia (BA) from other disease processes causing infantile cholestatic jaundice. The high-frequency ultrasonography (HUS) yields much improved spatial resolution and therefore, might show better image in BA diagnostic examination. The present study was to evaluate the HUS on the diagnosis of BA in infants with jaundice. METHODS Fifty-one infants with neonatal jaundice were scanned with ultrasonography. Images included gallbladder, bile duct, right hepatic artery (RHA), portal vein (PV) and triangular cord (TC) sign, magnetic resonance imaging and additionally, laboratory tests and histopathology reports were assessed. RESULTS Twenty-three BA and 28 non-BA cases were confirmed. The sensitivity, specificity, and accuracy of HUS were 91.3%, 92.9%, and 92.2%, respectively. All of these indices were significantly higher than those of conventional ultrasonography (P<0.01) and MR cholangiopancreatography (P<0.05). The HUS features, included a positive TC sign, an increased RHA diameter and RHA-diameter to portal-vein-diameter ratio (RHA/PV) and abnormal gallbladder, were important in the diagnosis of BA. CONCLUSIONS HUS provided better imaging of BA and should be considered as a primary modality in the differential diagnosis of infantile jaundice.