Carotid artery aneurysms are rare, however, serious complications may result--namely, rupture, thrombosis, or emboli. Five distinct clinical types of aneurysms are reported with different symptoms and treatment. Fusiform, saccular, false, and mycotic aneurysms are best treated with interposition autogenous vein grafting. Spontaneous dissection aneurysms are best treated initially with anticoagulation and follow-up angiography. Recanalization is the usual result. Meticulous surgical technique to prevent perioperative emboli is essential to prevent central nervous system complications.