ABSTRACT BACKGROUND: Perinatal asphyxia is a lack of blood flow or gas exchange to or from the foetus just before, during, or after birth. Perinatal asphyxia can have serious systemic and neurologic consequences like cerebral palsy, mental retardation, irreversible neurologic damage, and/or epilepsy. Ultrasound is a simple tool that can be used readily anytime at bedside. USG helps in identifying intracranial lesions like haemorrhages, periventricular leukomalacia, brain edema. Doppler parameters of anterior and middle cerebral artery like PSV, EDV, PI and RI helps in evaluating the cerebral blood flow velocity and vascular resistance. METHODS : This prospective observational study was done on 120 neonates referred to the Radiodiagnosis department with suspected hypoxic ischemic brain injury. Cranial ultrasound was done at <= 36 hours and at >= 72 hours along with the doppler study in all neonates. RESULT: Abnormal ultrasound findings were common in preterm neonates compared to term neonates. Germinal matrix haemorrhage and periventricular leukomalacia were the most common sonographic findings in preterm neonates and that of term neonates was cerebral edema. With increase in severity of clinical grades of HIE, there was decrease in the mean RI values of ACA and MCA. CONCLUSION: Transcranial ultrasound can be used as a valuable diagnostic tool for the management of hypoxic ischemic brain injury. Thus, by performing transcranial ultrasound and colour doppler at 36 hours, early diagnosis and intervention can be achieved. This can help reduce ominous complications and decrease morbidity and mortality.