The authors described a case of arteriovenous malformation (AVM) of the choroid plexus, and presented a review of literature. This 40-year-old male experienced a sudden onset of severe headache and vomiting on February 5th 1982. At the other hospital, CT scans revealed marked intraventricular hemorrhage, however his general condition was relatively good without a loss of consciousness, motor weakness and sensory disturbance. After about a month of conservative treatment, he was transferred to the Kochi Medical School Hospital. On admission, he had shown no neurological deficit except for slight occipital headache. Transfemoral cerebral angiography revealed an angioma of the choroid plexus, which was fed by the anterior and medial posterior choroidal arteries and drained into the internal cerebral vein. CT scans showed a small high density area due to the nidus of angioma at the interspace of bilateral frontal horns of the lateral ventricles. On March 25th 1982, using an anterior transcallosal approach, the angioma was totally removed. The histological diagnosis was AVM. The post-operative course was uneventful and the patient discharged without adding neurological deficit on April 12th 1982. Review of literature revealed 27 documented cases of angioma of the choroid plexus; 12 cases of AVM, 5 of cavernous angioma, 2 of telangiectasia, 1 of venous angioma and the other 7 of undefined description. Almost all cases were initiated with an episode of variable intracranial hemorrhage, particularly of intraventricular hemorrhage. Clinical course of them, however, were variable. On the contrast to male prevalence of AVM located in the other sites, the ratio of female to male was 2:1.(ABSTRACT TRUNCATED AT 250 WORDS)