Background: Introduction of prenatal ultrasonography (USG) in fetus diagnostic caused early detection of congenital urinary tract abnormalities. Dilatation of renal pelvis, which is detected in ultrasonography from 16 week of gestational age is the most common abnormality in fetal urinary tract. The aim of the study was to assess the frequency of congenital abnormalities in urinary tract in children with prenatal suspicion of anomalies. Material/Methods: The retrospective study included 100 children with prenatal suspicion of congenital abnormalities in urinary tract. Changes in urinary tract were detected in ultrasonography between 18-41 (mean 32,6±5,6) week of gestational age. Unilateral dilatation of urinary tract was found in 57% fetuses, bilateral dilatation in 31%, others anomalies in 12% fetuses. Results: Ultrasonography of urinary tract was done in all children in 1-122 (mean 17,5±20,5) day of life, cystourethrography in 93% of children, renal dynamic scintygraphy in 52%, renal static scintygraphy in 16% and urography in 39% of children. Congenital urinary tract abnormalities were detected in 63% of children. Transient dilatation of renal pelvis was observed in 25% of children. We didn't find any abnormalities in 12% patients. The most common changes in urinary tract were: ureteropelvic junction obstruction (22%), vesicoureteral reflux (15%), ureterovesical junction obstruction (7%), posterior urethral valve (7%) and polycystic renal dysplasia (7%). 33% children were qualified for invasive treatment. Conclusions: 1. Prenatal and postnatal ultrasonography of urinary tract allows detecting congenital abnormalities of urinary tract early age of life. 2. High percentage of abnormalities in urinary tract detected in prenatal ultrasonography orders cooperation between neonatologist, urologist and nephrologist.