Infectious intracranial aneurysms in infantile period are very rare, and there is no report of infectious intracranial aneurysm in preterm infant A 43-day-old female infant, delivered at 29 weeks of gestation, presented with massive intracranial hemorrhage. Eighteen days after diagnoses of necrotizing enterocolitis, sepsis, and meningitis, the baby became lethargic with rigid left limbs. Imaging studies revealed a large hematoma in the right temporoparietal region and adjacent lateral ventricle. During removal of fresh hematoma, an actively bleeding nodular mass, contiguous with the distal middle cerebral artery branch, was found and excised from the parent vessel. Pathologic examination revealed a ruptured infectious intracranial aneurysm. After surgery, her neurologic status improved and she was doing well at 12 months’ follow-up with mild spastic hemiparesis. To our knowledge, this is the first reported case of infectious intracranial aneurysm in the preterm infant, which was successfully treated with hematoma evacuation and resection of the aneurysm.