The clinical, radiological and pathological findings of four cases of primary intraventricular haemorrhage secondary to choroid plexus arteriovenous malformations (AVM) are described and the relevant literature reviewed. In three of the cases the diagnosis was confirmed or made at autopsy. The fourth case survived to undergo craniotomy followed by radiosurgery with excellent results. All AVMs originated in the choroid plexus of the lateral ventricle, and autopsy confirmation required a high degree of suspicion and the systematic microscopic examination of serial coronal sections of the ventricle with the clot in situ.