Present the sequential pattern of recognition of the fetal venous anomalies to improve the prenatal diagnosis. The anomalies of the fetal venous system are poorly documented. We present a descriptive study of the cases with diagnosis of fetal venous system anomalies between 2004 to 2008. For this description of patterns of recognition we use the 3D multiplanar technique and 2D conventional ultrasound. We present 20 patients with diagnosis of congenital venous system anomalies who diagnosis was made between 2004 to 2008. 5 patients with diagnosis of abnormal connection between central veins and fetal heart all of them with CHD. The mortality of this patients were 100%. 12 patients with persistant left superior vein cava. 2 cases with dilatation of umbilical vein and 1 case with ductal vein agenesis without portal circulation. The corrected study of anomalies of fetal venous system improve the prenatal diagnosis. In side of variables of pattern of recognition the anatomic study using the doppler color with 3D and 4D techniques.