To evaluate the prognosis and outcome of persistent left superior vena cava (PLSVC) in fetus with congenital heart disease. Retrospective study of 11 cases of PLSVC detected prenatally between 2003 and 2006 in our center. Maternal fetal medicine specialists and pediatric cardiologists did the prenatal evaluation. Posnatal follow–up was obtained in all cases. All cases were presented to the Prenatal Diagnosis and Fetal Advanced Therapy Committee of Colsanitas Clinic. Eleven cases with PLSVC were diagnosed. The diagnosis was made in the three vessel and trachea view when a supernumerary vessel to the left of the pulmonary trunk was identified, and in the 4-chamber view when two signs–a cyst at the lateral wall of the left atrium and dilated coronary sinus–were seen. In nine cases we found a structural anomaly in the heart: left ventricular hypoplastic syndrome (n = 2), double outlet right ventricle (DORV)(n = 2), conotruncal anomaly (n = 2), partial anomaly vein drainage (n = 1) and ventricular septal defect (VSD)(n = 2). In two cases PLSVC was an isolated finding. Of the VSD that were associated with PLSVC, one fetus had trisomy 13 and the other had hydrops. The fetus wuth DORV had a left isomerism syndrome. Of nine cases with PLSVC and a structural heart anomaly, seven fetuses died in perinatal period. 85% of these fetuses had anomalies in other systems and 75% were associated with complex heart disease. We believe that PLSVC associated with complex heart disease could be considered a marker of a poor prognosis. PLSVC could be a marker of congenital heart disease and is an indication for a detailed ultrasonographic and echocardiographic study.