Background: Assessment of safety and curative effect of microsurgical clipping anterior communicating artery (ACoAA) aneurysms through the right side Pterional approach in patients with dominant left A1 segment. Aim of Study: This study is to assess safety and curative effect of microsurgical clipping anterior communicating artery (ACoAA) aneurysms through the right side pterional approach in patients with dominant left A1 segment. Patients and Methods: The present study retrospectively was done on 25 cases with ruptured anterior communicating artery aneurysms with dominant left A1 circulation admitted to the emergency unit of the Neurosurgery department, Cairo University, Kasr Al-Ainy Hospital, between January 2019 and December 2020. The patients were assessed regarding their clinical outcome after surgical clipping. Results: This study was performed on twenty-five cases presenting with ruptured aneurysms and diagnosed with left A1 dominance. The study focused on assessment of safety and effectiveness of microsurgical clipping anterior communicat-ing artery (ACoAA) aneurysms through the Right Pterional approach in these cases. Regarding Intra-operative assessment, the right Pterional approach is a relatively short operation (av-erage 2.92 hours) that provides accessibility and convenience to the neurosurgeons, especially the right-handed. It's a secure and reliable approach that allows successful clipping of the an-eurysm. Admitting to the fact that 68% of operations had in-tra-operative complications showed serious clinical deficits in the post-operative period. Post-operative assessment reported 48% of post-operative complications however, 48% had good recovery with minimal disability, while 20% and 12% had moderate and severe disability respectively. Conclusion: In view of the results of this study, it could be concluded that the right Pterional approach is the best surgical modality used for microsurgical clipping of ruptured ACOM aneurysms in patients with left A1 dominance. It's convenient, safe, reliable, and efficient with the least operative complica-tions.