Two cases that were surgically treated with atherosclerotic aortic aneurysm, followed by innominate artery aneurysm are reported. The causes of these aneurysms were determined to be arteriosclerosis and idiopathic inflammation. Blood flow reconstruction surgery using grafts was performed on these two patients. In one case, we also employed an internal shunt technique to prevent brain ischemia. It was speculated that this type of aneurysm develops not only in cases of inflammation, but also in multifocal arteriosclerotic vascular diseases. This type of aneurysm will probably increase in the future.