Urinary tract malformations can often be demonstrated at a prenatal age. They are usually represented by urinary tract dilatations, the most frequently detected alteration at obstetric ultrasound examination, with an incidence of up to about 4.5% of pregnancies. Congenital uropathies, in which the etiopathological role of genetic factors is today generally recognized, cause 10–20% of cases of chronic renal failure in pediatric age. Many of these anomalies are included in the acronym CAKUT (Congenital Anomalies of the Kidney and Urinary Tract).