Abstract : Congenital anomalies of the kidney and urinary tract are the most common congenital diseases diagnosed in infants, which actually accounts for 15-20% of all congenital anomalies. The prevalence of these anomalies in the United States is estimated to be 3-6 persons per 1000, with a prevalence of 0.1% in prenatal ultrasound and 1% in post-natal sonography in the absence of any systemic disease. These anomalies are responsible for 34-59% of chronic kidney disease (CKD) and 39% of end-stage renal disease (ESRD) in children, affecting one's growth, puberty, and perception. Congenital renal and urinary malformations are a group of structural health problems that result from a defect in embryonic kidney development and account for approximately 30-60% of all congenital malformations. This cross-sectional study was performed to determine the prevalence of Congenital anomalies of the kidney and urinary tract (CAKUT) using ultrasound in neonates referred to Imam Khomeini Hospital of Ilam. The study population included all neonates referred to the neonatal ward of Imam Khomeini Hospital in Ilam, during the years 2018 to 2019. This study showed that the prevalence of CAKUT in neonates in Ilam city was higher than those in studies conducted abroad; also, hydronephrosis was the most common anomaly among different anomalies. The prevalence of congenital renal and urinary tract anomalies was significantly higher in preterm infants, LBWs, males, and mothers with a history of gestational diabetes