A 12 year old male admitted to our hospital with a complaint of poor weight gain. Abdominal ultrasonography suggested double inferior vena cava that the left one draining into right inferior vena cava (IVC) immediately after giving origin to right renal vein. Echocardiography revealed a drop-out appearance on interatrial septum and a second venous structure located at the left side of the abdominal aorta. Diagnosis of patent foramen ovale and double IVC was further confirmed by conventional angiography. Although rarely suspected, recent studies have revealed that IVC anomalies are not rare if anticipated and evaluated. The prevalence of double IVC is reported between 0.2% and 3% in general poulation. The left IVC typically ends at the renal vein which crosses anterior to the aorta in the normal fashion to join to the right IVC. In routine conditions, conventional angiography is not indicated in case of isolated double IVC. For our patient, we planned device closure of PFO because of reportedly increased risk of trombosis and embolism due to this rare venous anomaly.