Axillary artery aneurysms are most commonly caused by trauma, while atraumatic cases are very rare. Atherosclerosis, collagen tissue diseases, and mycotic infections are additional etiological factors for this type of aneurysms. Once developed, an aneurysm poses risk for hand ischemia or neurologic complications due to embolic events and neural compression. Due to this, diagnosis and treatment of an aneurysm are crucial. We report a case of giant bilateral axillary artery aneurysms developed as a consequence of atherosclerosis.