Summary This case report describes a patient with Hereditary Hemorragic Telangiectasia and a giant hepatic artery aneurysm. Aneurysms of the hepatic artery are the second most common form of visceral artery aneurysms. The causes of hepatic artery aneurysms are atherosclerosis in 30% of cases, arteriitides, periarterial inflammation, liver transplantation, and hepatic tumor embolization. To our knowledge no giant hepatic artery aneurysm has been described in relation to Weber-Rendu-Osler disease in the literature. These aneurysms probably develop because of hepatic arterio-venous fistulas and secondary to changes in arterial hemodynamics. The increased use of non invasive imaging techniques such as MRI before liver transplantation in patients with hereditary hemorragic telangiectasia reveals these asymptomatic aneurysms and makes it possible to choose the best therapeutic approach.