The most common site of internal carotid artery (ICA) aneurysms is at the posterior communicating artery (PComA) junction. Although ICA aneurysm surgery carries substantial risk, the ultimate outcome of patients with PComA aneurysms is better than those with aneurysms in other locations. The rate of successful surgical outcome increases when precise knowledge of the anatomy and understanding of the hazards associated with aneurysms in this region are combined with a well organized plan for the surgical approach. This article will describe details of the preoperative considerations, operative techniques, and surgical results for aneurysms arising at the ICA-PComA junction based on the 25-year personal experience of the senior author, comprising a total of 424 surgical cases.