OBJECTIVE: To evaluate prenatal management and to define the criteria of gravity for accurate assessment of the renal and overall prognosis of fetuses presenting malformations of the urinary tract. METHODS: We carried out a retrospective study of 127 cases of urinary tract malformation. We carried out descriptive statistical and univariate analyses as a function of severity criteria and the outcome of pregnancy. RESULTS: One-third of fetuses presented associated extrarenal malformations and 10% of the karyotypes were abnormal. There were more abortions in case of decrease in amniotic fluid volume (p < 0.001), extent of renal damage (p < 0.05), presence of associated extrarenal malformations (p < 0.05), early diagnosis of the malformation (p < 0.001) and presence of chromosomal syndrome (p = 0.01). In our study, there was an excellent correlation between prenatal data and pathological findings for the fetus following abortions for medical reasons or obtained during the surveillance of live-born children. Fetal biochemistry made very little contribution. CONCLUSION: In cases of urinary tract malformation, this work confirms the need for regular and frequent ultrasound scans, checking for the echographic factors indicative of gravity and for adapted karyotyping. It also demonstrates that pluridisciplinary management is necessary for the prenatal evaluation of renal and overall fetal prognosis.