The vertebral arteries have been hypothesized to be a source of recurrent emboli that obstruct the posterior circulation of the brain in children, but mechanisms for formation of such emboli have not been documented. An infant with Klippel-Feil anomaly experienced multiple embolic events in the posterior circulation, documented by serial computed tomography and cerebral angiography. Angiography identified a source for the emboli in the left vertebral artery. The value of lateral cervical spine radiographs in screening for bony abnormalities which may predispose to arterial anomalies is demonstrated.