Three hours after sniffing a dose of heroin, a 30-year old man developed right hemiplegia with aphasia. Magnetic resonance imaging of the brain showed an infarct in the territory of the left anterior choroid artery. Cerebral vascular accidents occurring as complications of heroin addiction are rare: a review of the literature yielded only 13 documented cases. The main characteristics of these strokes are analysed and their pathogenetic mechanisms (immuno-allergic vasculitis, vascular spasm) are discussed.