Using Doppler color flow mapping, intracranial hemodynamics were evaluated for 65 normal neonates as well as 7 neonates with symptomatic patent ductus arteriosus (sPDA) . The pre-ejection period (PEP), ratio of PEP to ejection time (PEP/ET) in the ascending aorta, as well as both the middle cerebral artery (MCA) and the basilar artery (BA) were measured. For normal neonates, there were no significant postnatal changes in the PEP and the PEP/ET of the aorta, MCA and BA. However, for neonates with sPDA, the PEP had shortened and the PEP/ET had decreased in the aorta, MCA and BA as compared to those of normal neonates. The time difference between the PEP of the aorta and that of the cerebral artery (EPEP) were also calculated. The OPEP of both MCA and BA were considered to have been affected by the characteristics of the vessel between the aorta and the cerebral artery. In normal neonates, the ΔPPEP of BA showed no significant postnatal changes. However, the ΔPEP of MCA shortened significantly after birth (p<0.05) .