The author choroidal artery syndrome is a rare disorder associating, in its complete form, a hemiplegia, a hemianesthesia, and a homonymous lateral hemianopia. Four cases are reported in which the diagnosis was confirmed by a CT scan, which demonstrated a low density area in the posterior part of the posterior limb of the internal capsule, sparing the thalamus medially, and extending laterally to the apex of the pallidum thus corresponding to the area supplied by the anterior choroidal artery. The incomplete forms of this syndrome and clinicopathological correlations are discussed.