Rationale:Moyamoya disease (MMD) is a cerebrovascular structural disorder characterized by bilateral stenosis and obstruction of the internal carotid artery, anterior cerebral artery, and initial segment of a middle cerebral artery, as well as the aberrant formation of collateral arteries at the base of the brain. Moyamoya disease with distal anterior choroidal artery (AChA) aneurysm is extremely uncommon. At present, the treatment of Moyamoya disease with aneurysm mainly includes conservative treatment and surgical treatment, including revascularization, endovascular therapy and microsurgical clipping or resection. Interventional therapy is the first treatment of choice. For those whose paths are tortuous and inaccessible and intervention fails, I successfully excised them through craniotomy.Patient concerns:The 38-year-old male patient, diagnosed with Moyamoya disease 11 years ago and was hospitalized for multiple intraventricular hemorrhages throughout that time. During the 11 years, the patient was hospitalized for intra ventricular hemorrhage for several times. The patient was diagnosed as moyamoya disease for many times by digital subtraction angiography, but he was recommended to come to our hospital for cerebrovascular bypass surgery 3 months after each hemorrhage, but he did not come to our hospital until the next intraventricular hemorrhages.Diagnoses:This recurrent intraventricular bleeding was suspected to be caused by MMD, and a digital subtraction angiography of the brain revealed an aneurysm of the distal AChA.Interventions:Interventional therapy was the first choice. During the operation, transcatheter aneurysm embolization was tried. Finally, interventional therapy was abandoned because the vessels were too thin and tortuous and the guide wire could not pass through. After detecting the aneurysm using computerized tomography angiography, the distal AChA aneurysm was resected through the lateral interventricular foramen of the corpus callosum, and the corpus callosum was parted along the interhemispheric fissure to access the third ventricle.Outcomes:On the 21st postoperative day, the patient improved, recovered to a Glasgow Coma Scale score of 15.Lessons:We conclude that craniotomy is a satisfying alternative in patients with MMD complicated by perforated distal AChA aneurysm hemorrhage if the vascular prerequisites for endovascular treatment are not accessible and the patient has a favorable prognosis.