We describe two adults with stroke-like migraine attacks after radiation therapy (SMART syndrome), propose revised diagnostic criteria, and review the previously reported patients. ‘SMART’ is an acronym for a newly recognized syndrome which occurs as a delayed consequence of cerebral irradiation and consists of prolonged, unilateral, migrainous neurological symptoms with transient, dramatic cortical gadolinium enhancement of the affected cerebral hemisphere and is sometimes punctuated by generalized seizures and ipsilateral EEG slowing. Although the neurological symptoms can last for weeks, full recovery occurs. An appropriate evaluation should exclude alternative explanations.