OBJECTIVE: To investigate the clinical characteristics of aneurysms of the ophthalmic artery segment of the internal carotid artery and the treatment methods of microsurgery. METHODS: The clinical data of 40 patients with aneurysm of the segmental artery of the internal carotid artery from December 2006 to September 2010 in our hospital were retrospectively analyzed. There were 13 male and 27 female cases, including one combined anterior communicating artery aneurysm, four combined bilateral internal carotid artery ophthalmic segment aneurysms, four combined posterior communicating artery aneurysms, one combined posterior inferior cerebellar artery aneurysm, one combined middle cerebral artery aneurysm, and one combined basilar artery aneurysm. Results: The prognosis of the operated patients was evaluated by GOS score. 33 cases recovered well, 1 case had mild disability, 2 cases had severe disability, and 4 cases died; postoperative follow-up ranged from 2 to 46 months (mean 21.3 months), and complete aneurysm clamping was confirmed by cranial CTA or DSA examination. Conclusion: Clamping of aneurysms in the ophthalmic segment of the internal carotid artery via the pterygoid approach is a safe and effective method. Individualized treatment should be selected according to the patient’s preoperative Hunt-Hess classification as well as the site, size, and morphology of the aneurysm and the hospital’s equipment conditions. Preoperative perfect imaging and the application of microvascular Doppler during surgery are important to reduce postoperative complications and improve prognosis.