Susac syndrome (SS) is a rare immune-mediated disorder characterized by occlusion of arterioles associated with the brain, inner ear and retina. The main clinical manifestations of SS are encephalopathy, branch retinal artery occlusion and sensorineural hearing loss. However, they always appear one after another, and always lead to missed diagnosis and misdiagnosis. Brain magnetic resonance imaging, fundus fluorescein angiography and audiometry are helpful for the early diagnosis of SS. Glucocorticoid, intravenous injection of immunoglobulins and immunosuppression are suggested for the comprehensive treatment of SS.