Introduction: Cerebral aneurysms in pediatric age are rare. In early childhood, they appear before the age of 2 years and are related to a high incidence of injuries along the middle cerebral artery, in its distal part, and in the vertebrobasilar system. The etiology can be idiopathic, traumatic, and fungal. Aneurysm obliteration should be as early as possible in patients with low surgical risk.

Clinical Case: The case of a 5-month-old patient with no significant medical history is presented, with a 2-day illness time, signs of irritability, vomiting, and tension in the fontanelle. A cerebral tomography was performed showing a predominantly right subcortical frontal fine subarachnoid hemorrhage and an angio-tomography (Angio-TEM) that showed an aneurysm of the anterior cerebral artery. The cerebral angiography study revealed a dissecting aneurysm of the left A2-A3 segment that involved the division of the left anterior cerebral artery into a pericallosal and marginal callus artery. Embolization was performed using 4 coils and Histoacryl® to close the parental artery. He had a seizure crisis from a left marginal callus infarction that was medically controlled. The clinical evolution was good, being discharged on the 7th day of hospitalization.

Conclusion: Pediatric cerebral aneurysms are a rare pathology and in patients with low surgical risk, such as our patient, they should be treated as soon as possible to decrease morbidity and mortality.