These days, a less invasive surgery is stressed. One current thought is that the endovascular surgery itself is the less invasive and safer surgery for a cerebral aneurysm, and not the microsurgery. Is this true? We have evaluated the merits and demerits of each method. Our conclusion is as follows. Endovascular Surgery should be considered as an alternative, only for the specific patients. Microsurgery itself retains its position of the first treatment of choice for a cerebral aneurysm. "Less invasive" cannot be equated with "less dangerous". We will show the above reasons using slides and videotapes of several patients.