Stroke is the leading cause of disability and the third leading cause of death in the USA. Ischemic and hemorrhagic strokes must be distinguished since treatment is quite different. Ischemic strokes account for 80 % of the total and recent advances in management of brain ischemia have added valuable options to the physicians' armamentarium. Wise selection and targeted treatment of patients is of paramount importance. Properly treated patients benefit significantly, while those erroneously diagnosed as ischemic stroke are exposed to potentially harmful side effects of therapy. Stroke can present in the form of several different clinical syndromes some of which are difficult to identify. Conversely, there are numerous conditions whose clinical presentation closely resembles stroke, also known as stroke mimics. Ancillary testing, especially imaging, is a crucial part of diagnostic evaluation, while clinical judgment, thorough knowledge of cerebrovascular anatomy and familiarity with characteristic stroke syndromes remain indispensable even in this era of technological advance.