The authors present a case in which multiple cerebral and pulmonary arteriovenous malformations (AVMs), a brain abscess, and a recurrent subcutaneous abscess were found concurrently in a 52-yearold male. He was admitted to our hospital for evaluation of a subcutaneous abscess in the right nuchal area and a right occipital AVM that had been detected at another hospital. Of his eight siblings, three had died of cerebrovascular disease (one in childhood and two as young adults), one had died of unknown causes in childhood, one had been hemiplegic since infancy, one had recently undergone removal of a pulmonary AVM, one was killed in World War II at the age of 24 years, and the remaining sibling was healthy. He had had surgery for a right occipital brain abscess three years prior to this admission. A general examination revealed no abnormalities other than the painful right nuchal mass. Neurological evaluation disclosed left homonymous hemianopsia, which was probably a result of his previous surgery for the right occipital brain abscess. Cerebral angiography showed AVMs in the right parietal (2 × 2 cm), right occipital (1.5 × 1.5 cm), and right cerebellar areas (1 × 1 cm). Digital subtraction angiography of the lung revealed multiple bilateral AVMs. The cerebral and pulmonary AVMs were removed in a two-stage operation. Although this case did not correspond precisely to the triad of hereditary hemorrhagic telangiectasia (HHT), the authors consider it to be related to HHT, since that syndrome is often complicated by multiple cerebral and pulmonary AVMs.