Bilateral absence of the superior vena cava (SVC) is an uncommon congenital vascular anomaly, mainly asymptomatic, usually undetected, and often associated with other cardiac anomalies. Though usually harmless and totally innocent, this vascular anomaly might complicate cardiovascular surgery, the insertion of a central venous catheter and the transvenous placement of a pacemaker. This SVC anomaly is still not well known, underdiagnosed and its incidence is much higher than described. A better understanding of this anomaly and its detection could play a key role in avoiding its potential complications. We are sharing a case of a female adult, with no medical history, who presented herself to the department of visceral surgery with a collateral venous circulation of the upper thorax, that was at first, mistaken for a portal hypertension syndrome, findings were pushed to finally conclude a bilateral absence of the SVC.