A patient with subdural hematoma associated with multiple mycotic intracranial aneurysms is reported. A 22-year-old woman presented with headache and disturbance of consciousness. A CT showed subdural hematoma at the tentrium and the left cerebral convexity. Conservative treatment and was used and she was discharged 10 days later. However, follow-up CT demonstrated a parenchymal hematoma in the right posterior temporal lobe. Cerebral angiography demonstrated a large right posterior cerebral aneurysm and multiple right middle cerebral aneurysms. A cardiac ultrasonography showed a verruca at the mitral valve. The posterior cerebral aneurysms increased in size and one new middle cerebral aneurysm appeared at follow-up angiography one week later. Endovascular treatment with coils was applied for the right posterior cerebral aneurysm, and others were treated with antibiotic therapy under serial observation, using MR angiography. She was discharged without any symptoms two months after embolization. Follow-up angiography at one year after embolization showed disappearance of the aneurysms. The possibility of mycotic aneurysm should be considered in the differential diagnosis of non-traumatic acute subdural hematoma.