Persistent left side superior vena cava (PLSVC) is an uncommon venous anomaly that occurs as a result of persistence of caudal part of left anterior cardinal vein (LACV). When isolated, PLSVC is of no hemodynamic significance and is considered as a benign variant. However, a detailed fetal and post-natal echocardiogram is advised to rule out any structural heart defects. Its presence should be documented as it is important while doing cardiac procedures later in life.