A 69-year-old woman with a history of Hodgkin's lymphoma at age 17 was admitted to our hospital with 3 weeks of progressive dyspnoea on exertion. Her medical history and physical exam were concerning for superior vena cava (SVC) syndrome and while her workup did indeed reveal such, its aetiology was not due to a compressive mass associated with malignancy. Rather, she developed chronic thromboses in the setting of radiation-induced venous fibrosis. This case report details her case and explains the key clinical concerns, pathophysiology and incidence of radiation-induced SVC syndrome.