Hyperintense vessels are frequently observed on fluid-attenuated inversion recovery imaging in acute ischemic stroke patients. Some investigators suggest that a hyperintense vessel sign in patients with middle cerebral arterial occlusion results from collateral blood flow originating in neighboring arterial territories, especially via pial collaterals. We report two cases of acute proximal middle cerebral arterial infarction that exhibited hyperintense vessels signs on fluid-attenuated inversion recovery imaging accompanying pial collaterals as confirmed by cerebral angiography