Introduction: A giant cerebral aneurysm is one that reaches a size greater than 25 mm in diameter, and whose complications are rupture and a mass effect like a tumor. The complex anatomy of the posterior communicating segment and the size of the aneurysm make it challenging to treat surgically, so the best definitive treatment option for this type of pathology is the Endovascular route, which seeks obliteration and exclusion of the aneurysm.

Clinical case: A 65-year-old female patient with a history of high blood pressure and a religion of being a Jehovah's Witness, was admitted with an illness of 5 months characterized by headache, dizziness, eyelid ptosis, left hemiparesis 4/5, on a Glasgow coma of 15 points. Cerebral angiography showed a giant unruptured aneurysm of the communicating segment of the right internal carotid artery, for which it was embolized with a stent and penumbra coils using the “Jailing” technique, successfully closing the entire aneurysm.

Conclusion: Giant aneurysms are complex lesions, for which Endovascular therapy is a safe and effective alternative with a lower complication rate.