We reviewed surgery for 40 paraclinoid aneurysms with special interest in the relation between the location of aneurysm and surgical procedure. In cases with small C2 anterior wall and ophthalmic aneurysm, anterior clinoidectomy was not necessary. Anterior clinoidectomy was necessary for clipping of C2 posterior, C2 medial, C2-3 medial, C3 medial aneurysm. In cases with small C2 posterior or medial aneurysm, a contralateral pterional approach provided sufficient operative field for clipping. Adequate clipping for C3 medial and large C2-3 medial aneurysm was not achieved without dissection of the distal ring. Proximal control with balloon catheter placed in the cervical internal carotid artery was safe and useful for temporary occlusion of proximal artery and intraoperative DSA. Intraoperative DSA provided valuable information for correct clipping and complete preservation of the internal carotid artery. Ischemic visual field defect occurred in 2 of 8 cases whose superior hypophyseal artery was sacrificed. Although sacrifice of this artery may be acceptable in cases with large aneurysm involving superior hypophyseal artery, preservation of this artery should be attempted in cases with small aneurysm related with superior hypophyseal artery.