Renal venous thrombosis (RVT) is a rare event in neonates and infants. Its incidence varies from 0.5 per thousand concerning admissions in neonatal intensive care units to 0.5% in autopsic findings. Some cases may occur in the antenatal period. Clinical presentation in infants includes a mass in the flank. hematuria and thrombocytopenia. We report a case of RVT which was diagnosed at 34 weeks' gestation by ultrasound in a fetus showing cardiotocographic signs of fetal distress. We observed the typical pattern reported by pediatric radiologists: renal enlargement, loss of the cortico-medullary boundary, echoic streaks following the direction of interlobular veins, lack of definition of renal sinus echoes and loss of venous flow in the right kidney by Doppler velocimetry. After delivery by caesarean section and transient hyperbilirubinemia and moderately impaired renal function the infant weighing 2435 g had a full recovery at 1 week and a normal evolution at 1 month of life.