Capsular warning syndrome (CWS) is a specific form of transient ischemic attack with low incidence; however, it may proceed to acute cerebral infarction with high possibility. In this review, we summarized the pathogenesis and mechanisms, clinical symptoms, imaging features, treatment and prognosis of the CWS, hoping to attract the clinicians' attention on it and to promote the early diagnosis of patients with CWS, and thus to improve the prognosis of CWS.