PURPOSE: To evaluate intracerebral resistive index (RI) values in neonates with congenital heart disease and to investigate their changes after the corrective surgery of the congenital heart disease. MATERIALS AND METHODS: Sixty nine neonates with congenital heart disease who underwent brain ultrasonography were included. Resistive index values were obtained at the genu portion of the anterior cerebral arteries through the anterior fontanelles. The patients were divided into 4 groups according to the presence of associated patent ductus arteriosus (PDA) and intracranial RI values. We evaluated the types of congenital heart disease that could influence RI values. RESULTS: Resistive index values were statistically higher in patients with PDA than in patients without PDA (p<0.05). RI values were higher in cases of large PDA with left-to-right shunt, but within the normal range in cases of small or nearly closing PDA or large PDA with bidirectional blood flow or with right-to-left shunt. For those patients without PDA, RI values were higher when patients had pulmonary atresia with multiple collateral vessels into the lung or when truncus arteriosus was present. RI values were also high in patients with hypoplastic left heart syndrome. RI values were normalized after the ligation of PDA, but patients with hypoplastic left heart syndrome showed persistently high RI values even after the Norwood's operation with Blalock-Taussig shunt. CONCLUSION: RI values are influenced by various congenital heart diseases except PDA. Therefore, the presences of the congenital heart disease and its hemodynamic changes should be taken into consideration in the evaluation of the intracranial RI values using Doppler ultrasonography.