Superior vena cava syndrome (SVCS) is a rare and life-threatening condition caused by the obstruction or compression of the superior vena cava, commonly due to malignancies, such as lung cancer. Diagnosing SVCS can be challenging due to its nonspecific symptoms that overlap with other conditions, such as angioedema. Making accurate differentiation may be critical for timely and appropriate patient treatment. This case report presents a 60-year-old female patient who was initially misdiagnosed with angioedema. However, after her condition showed no improvement despite implementation of multiple treatments, further investigation led to the accurate diagnosis of superior vena cava syndrome (SVCS). The presented delay in diagnosis highlights the difficulty in recognising SVCS, a condition that mainly presents as facial and upper body oedema. This case emphasises the need for thorough differential diagnosis, careful clinical examination, and heightened awareness of SVCS, to avoid misdiagnosis and ensure proper management.