INTRODUCTION: A persistent left superior vena cava is found in 0.3-0.5% of the general population and in up to 10% of patients with a congenital cardiac anomaly. It is the most common thoracic venous anomaly and is usually asymptomatic. Being familiar with such anomaly could help clinicians avoid complications during placement of central lines, Swan-Ganz catheters, PICC lines, dialysis catheters, defibrillators, and pacemakers. CASE PRESENTATION: We describe a case of persistent left superior vena cava that was noted after placement of a central line. Mr JJ is a 41 year old African American man who was hospitalized for evaluation and management of alcoholic necrotizing pancreatitis. He required multiple central lines placements. He was noted to have a persistent left superior vena cava that was not recognized initially and thus lead to an unnecessary extra central line placement. DISCUSSION: This anatomic variant may pose iatrogenic risks if it is not recognized by the clinician. A central catheter that tracks down the left mediastinal border may also be in the descending aorta, internal thoracic vein, superior intercostal vein, pericardiophrenic vein, pleura, pericardium, or mediastinum. CONCLUSION: Our case is significant because the patient had two extra central venous catheter placements. This case strongly demonstrates the importance of knowing the thoracic venous anomalies.