Thrombotic venous obstruction in patients with a tunnelled central venous catheter is a cause of superior vena cava syndrome that is not routinely encountered by emergency physicians. Diagnosis requires identifying patients at risk (e.g., those under treatment for cancer and those who have a tunnelled central venous catheter), recognizing the signs and symptoms of superior vena cava syndrome, usually dyspnea and dilated neck or thoracic veins, and imaging the venous obstruction using computer tomography or sonography. Management involves anticoagulation and local thrombolytic administration. We report the case of a 28-year-old woman who presented with a 2-day history of face, chest and bilateral arm swelling who had been receiving maintenance chemotherapy for acute lymphoblastic leukemia through a Hickman® catheter. This case demonstrates the need to be vigilant for thrombus formation in patients with long-term, indwelling central venous catheters.