To evaluate the prenatal diagnosis of agenesis of ductus venosus (ADV) and portal venous system (PVS) anomalies and describe the outcome of these cases, either isolated or associated. We evaluated the intrahepatic vascular system regarding the presence of normal umbilical drainage and PVS characteristics in the second and third trimester of pregnancy. The associated anomalies and umbilical venous drainage were noted. Follow-up was performed at six months follow-up. Ultrasonography was performed in 3517 cases. A total of 19 cases were prenatally diagnosed: 18 ADV cases, seven abnormal PVS cases, and six associations of the two anomalies. We noted an incidence of 5.1‰ and 1.9‰ for ADV and PVS anomalies, respectively. Out of the 18 ADV cases, 27.7% were isolated. Five cases (26.3%) presented genetic anomalies. PVS anomalies were found in 33.3% of the ADV cases. ADV was present in 85.7% of the PVS anomalies. DV and PVS abnormalities were found with a higher than reported frequency. Normal DV is involved in the normal development of the PVS. Additional fetal anomalies are the best predictor for the outcome of ADV cases. Evaluation of PVS represents a powerful predictor for ADV cases and addresses the long-term prognosis.