We describe a case report of a 49-year-old man admitted to a cardiology unit with a series of arrhythmias with no initially obvious aetiology. Further assessment and the use of cardiac magnetic resonance imaging and histology allowed a diagnosis of cardiac sarcoidosis to be made. Cardiac sarcoidosis is a major cause of death in patients with systemic sarcoidosis. Cardiac magnetic resonance imaging is an additional diagnostic tool for this condition without ionizing radiation exposure.