Endovascular surgery is suitable for both large and giant aneurysms, although additional long-term studies are needed. Use of coils to occlude aneurysms is becoming standard therapy. Endovascular treatment may allow occlusion of aneurysms with little brain trauma and without craniotomy or surgical vessel preparation. Factors that contribute to a good outcome following subarachnoid hemorrhage (SAH) include successful repair of the primary bleeding site, early clot removal, prevention of vasospasm, and prevention of rebleeding. Treatment approaches include both surgical and endovascular modalities.