Most reports on small infarcts in the territory of the deep perforators that arise from the internal carotid artery and its branches have focused on the anatomical structures. Recently, it has become possible to map the territories of the deep perforators from the carotid system, based on matching previous anatomical studies with recent data from computed tomographic and magnetic resonance imaging studies. The middle cerebral artery gives origin to two main groups of perforators: the medial and lateral lenticulostriate arteries. Rarely, the thalamotuberal artery may take origin from the middle cerebral artery but much more commonly it originates from the posterior communicating artery. The anterior cerebral artery gives origin to the anterior lenticulostriate arteries and the recurrent artery of Heubner. The anterior choroidal artery takes its origin from the internal carotid artery and exceptionally from the middle cerebral artery. In addition, a small group of perforators comes directly from the internal carotid artery. The anatomical structures supplied by these perforators are described, and a map of the territories is proposed.