We present two patients with hereditary hemorrhagic telangiectasia (HHT) accompanied by multiple hepatic arteriovenous malformations (AVMs) whose cranial MRI demonstrated high signal intensity in the basal ganglia on T1-weighted images. Manganese levels in peripheral blood were very high in both patients. These two cases indicate that there may be a significant relationship between high intensity basal ganglia and multiple hepatic AVMs. While the precise mechanism of the signal alternation in the basal ganglia is unproven, high blood levels of manganese in these patients suggest that abnormal intensity in the basal ganglia may be due to deposition of manganese.