Cardiac tamponade is a life-threatening medical emergency and can arise in many clinical situations. We present the case of a 59-year-old man with adrenoleukodystrophy and Addison’s disease who was admitted to the emergency department with severe abdominal pain that turned out to be cardiac tamponade of unknown aetiology. An association between cardiac tamponade and Addison’s disease has been reported in the literature, so this aetiology should be considered in the differential diagnosis for patients presenting with unexplained cardiac tamponade.