Due to the widespread use of obstetric ultrasound an increasing number of congenital malformations are diagnosed prenatally. Some of these can be treated in utero. A 17 week-old fetus with a posterior urethral valve was diagnosed due to a dilated bladder, bilateral hydronephrosis and oligohydramnios. An ultrasonically guided vesicoamniotic shunt was successfully placed in utero at 24 weeks of gestation in order to prevent development of dysplastic kidneys and hypoplastic lungs. Transurethral valve resection was performed five months postnatally. The one year-old infant is now well and has one normally functioning kidney.