This is a case report of an incidental diagnosis of persistent left superior vena cava (PLSVC). The diagnosis was suspected after a peripherally inserted central catheter (PICC) was placed and a postinsertion chest radiograph was conducted. PLSVC is a vascular anomaly that is usually diagnosed as an incidental finding. Here, we discuss the tests performed to confirm the diagnosis and the 3 variants of PLSVC. Nurses who place PICCs are likely to run across this abnormality on postinsertion chest radiograph and knowing the diagnostic test to order to confirm the diagnosis is key in expediting patient care.