Ultrasonography has made an enormous impact on the investigation of urinary tract in pediatric practice. It has become the primary imaging modality in urinary tract infection in children. Posterior urethra is imaged through trans-perineal approach and posterior urethral dilatation characteristic of PUV can be identified or a hidden calculus in the posterior urethra be revealed. The renal parenchymal echopattern is compared with adjacent organs. Renal cortex is normally less echogenic than hepatic or splenic parenchyma. The medullary pyramids are hypoechoic relative to the cortex. The corticomedullary junction is demarcated by the arcuate arteries, which are seen as small echogenic foci. Normal fetal kidneys should be routinely imaged by 16 weeks of gestational age as paired, hypoechoeic, ovoid, para spinal structures in the posterior mid-abdomen.