Cerebral arteriovenous malformations (AVMs) are considered to be congenital disorders. However, their familial occurrence has so far been described in only 19 families in the literature. The authors report on two cases in one family and review the literature. A 45-year-old female subject with sudden onset of headache and vomiting due to a subarachnoid haemorrhage from a small AVM in the posterior part of the corpus callosum near the midline on the left side was studied. Irradiation of the AVM using Leksell's gamma knife led to its complete obliteration. Her older sister presented with temporal seizures at the age of 49 and later also with left hemiparesis, left hemihypaesthesia and dizziness - caused by a large AVM in the right temporal lobe. This AVM was treated by a combination of embolization and irradiation by the Leksell's gamma knife.