The treatment of large and giant paraclinoid carotid artery (CA) aneurysms often requires the use of suction decompression for safe and effective occlusion. Both open and endovascular suction decompression techniques have been described previously. In this article the authors describe a revised endovascular suction decompression technique that provides several advantages in the treatment of large and giant paraclinoid and CA aneurysms. A 51-year-old woman presented with a relatively brief history of progressive visual loss in the right eye, nonspecific headache, and an afferent pupillary defect. After angiography studies had been obtained, it was determined that she had a giant right paraclinoid internal CA aneurysm with a dome size of approximately 26 mm on the right and a neck diameter of 10 mm. A modified technique was performed in which suction decompression was used. With the aid of a No. 7 French Concentric balloon guide catheter (Concentric Medical, Inc., Mountain View, CA) and application of a temporary clip distal to the aneurysm, the aneurysm was trapped and decompressed using retrograde suction through the guide catheter when the balloon was inflated. After satisfactory placement of three permanent clips, an intraoperative angiogram obtained through the same guide catheter confirmed CA patency. The aneurysm was then punctured and aspirated, ensuring complete occlusion of the aneurysm sac and reconstruction of the parent vessel. The patient made an excellent recovery and did not suffer any complications. She did not experience worsening in her vision. This technical modification to endovascular suction decompression allows several potential advantages, including higher volume decompression and the ability to deliver endovascular devices to distal arterial locations.