Objective: To evaluate the relationship of fetal urinary system anomalies with aneuploidy and additional structural malformations, to compare thepreliminary diagnoses made in the prenatal period with the results of the postnatal period. Methods: Two hundred eighty-two cases diagnosed as fetal urinary system anomaly in our clinic between 2016-2019 were evaluated within the scopeof the study. Age, gestational week, gravida, parity, fetal gender, type of anomaly, presence of additional anomaly, prenatal diagnosis method, fetalkaryotype result, termination status and postnatal results were recorded. Results: Hydronephrosis (HN) was in the first place among fetal urinary system anomalies. When congenital malformations accompanying urinarysystem anomalies were examined, central nervous system anomalies were the most common group with 26.4%. Urinary system anomalies, which are most frequently associated with additional anomalies; bilateral renal agenesis (50%), bilateral multicystic dysplastic kidney (50%) and extrofia vesica(50%). Considering the karyotype results, trisomy was observed in 26% of the cases, PKHD1 in 4% and triploidy in 2%. According to the karyotyperesult, when the group with normal karyotype and trisomy group was compared, the difference between the presence of additional anomalies(p=0.004), bilateral HN (p=0.012) and termination results (p=0.002) was found statistically significant. The rate of cases followed in pediatric surgeryclinic/outpatient clinic in the postnatal period is 26% and 38.2% of these cases have undergone surgical intervention. Conclusion: Appropriate diagnosis, follow-up and treatment of urinary system anomalies that have a broad clinical spectrum, with a multidisciplinaryapproach, are of great importance in both the prenatal period and the postnatal period.