A cavernous malformation is known to be accompanied by developmental venous anomalies; however, a concomitant arteriovenous malformation (AVM) is rare. We report a case of a cavernous malformation and AVM. A 14-year-old male adolescent, with a family history of cavernous malformation and concomitant AVM underwent surgical resection of the symptomatic left frontal lobe AVM.Intraoperatively, we detected a concomitant cavernous malformation. Cavernous malformations concomitant with AVMs are rare. The anomaly in our patient may be attributable to venous hypertension secondary to a juvenile AVM or a genetic association, based on the patient's family history.