Three-dimensional (volume) magnetic resonance angiography is a noninvasive technique that images the intracranial and cervical arterial vasculature without contrast agents. Twenty-four children with strokes had combined parenchymal magnetic resonance imaging and magnetic resonance angiography 1 day to 4 years after acute presentation. Eight had had prior intra-arterial angiography. Eighteen magnetic resonance angiographic studies showed arterial stenosis or occlusion in the vascular distribution of magnetic resonance image-defined brain infarction and, in 7 children, in the same location as previously defined abnormalities on intra-arterial angiography. One child had a normal intra-arterial angiogram and magnetic resonance angiogram. The other 5 children with normal magnetic resonance angiographic studies included 3 with presumed embolic disease, 1 with meningitis, and 1 with Crohn's disease-related vasculitis. Collateral flow patterns could be determined in 4 children. Artifact presenting as filling defects in vessels was present in 10 studies, but did not interfere with interpretation of 8 studies. Combined magnetic resonance imaging/magnetic resonance angiography provides a screening technique to evaluate noninvasively brain parenchyma and vasculature in children with suspected large-vessel abnormalities, allowing selection for intra-arterial angiography and serial monitoring of vascular abnormalities over time and during therapeutic intervention.