Background:Asphyxia is an important cause of acute kidney injury (AKI) and transient kidney impairment, there is a high incidence of AKI among the asphyxiated infants (50 – 72%). The normal renal ultrasound appearance in a neonate typically shows higher cortical echogenicity than in older child. Normally the parenchymal echogenicity is equal to or greater than that of liver and spleen. Doppler examination of the renal artery includes complete evaluation of the kidneys. Left and right decubitus patient positions are preferred for the kidney examination (left decubitus for the right kidney and vice versa). Both kidneys are examined carefully with respect to size, echogenicity and smoothness of outline, together with assessment of the corticomedullary differentiation.There are two approaches are used in Doppler examination, anterior abdominal approach and flank approach.