We studied 69 infants who had urinary tract abnormalities detected by antenatal ultrasound examination. There were 21 intrauterine or immediate neonatal deaths; in all 21 infants, severe bilateral renal disease incompatible with life was found at autopsy. Six of the live-born infants with abnormal results of antenatal ultrasound examinations had a normal urinary tract after birth. Of the remaining 42 infants, the prenatal diagnosis was confirmed with renal ultrasound and other studies during the first week of life. Twenty-one of 42 infants had bilateral renal disease. We obtained follow-up data on 19 of 21 of these infants. Twelve of 19 had obstructive uropathy that was treated surgically. After one to 51 (mean, 18) months of follow-up, renal function varied. Ten of 19 patients had a calculated glomerular filtration rate greater than or equal to 79 mL/min/1.73 m2. One infant required long-term ambulatory peritoneal dialysis. Renal function (glomerular filtration rate, 74 +/- 5 mL/min/1.73 m2) and growth (height percentile, 41 +/- 8) were unexpectedly good considering the severity of the urinary tract abnormalities. Prenatal detection of bilateral renal disease followed by careful medical and surgical management results in a favorable outcome with good growth and renal function.