The treatment of cerebral aneurysms aims at the complete elimination of the aneurysm from the circulation. In the case of subarachnoid hemorrhage (SAH), early management prevents rebleeding and in incidental aneurysms, future rupture is to be prevented. Standardization of surgical techniques and optimized collateral measures have reduced the morbidity and mortality of early operations in SAH to 10% and 15%, respectively, in most series. As an alternative, endovascular techniques are being developed which attempt to obliterate the aneurysmal sack by packing it with detachable platinum-coils. A major difference between clipping and coiling is the closure of the aperture by the surgical clip which approximates the vessel walls. During coil embolization, that aperture stays open, allowing in some cases further compaction of the coils in subsequent months and years. Recanalization attributable to compaction depends on the size of the aneurysm and may necessitate repacking in up to 40% of the cases (aneurysms > 25 mm). As for the risk of rebleeding, a recanalized aneurysm is comparable to a partially clipped aneurysm. As the surgical results from early and delayed operations were obtained in randomized controlled studies, such randomized comparative studies will need to be applied to assess the value and risks and long-term results of endovascular strategies.