Wallenberg's syndrome is the clinical manifestation of the obliteration of arterial blood vessels supplying the dorsolateral part of the medulla oblongata, the posterior inferior cerebellar artery being involved in most cases. A patient is described in whom the typical features of Wallenberg's syndrome correlated with cystic necrosis in the perfusion area of the posterior inferior cerebellar artery. A craniopharyngioma spreading along the pons and involving the posterior inferior cerebellar artery, the basilar artery, and its branches was found to be responsible for the infarction of the dorsolateral medulla oblongata.