The authors report an unusual case of a traumatic aneurysm of the right superior cerebellar artery (SCA). A 22-year-old woman presented with continuous headaches that appeared 15 days after she experienced closed head trauma as a result of a cycling accident. Computerized tomography scanning performed 3 months later showed a nodular lesion on the free edge of the tentorium, which mimicked a meningioma. The aneurysm was identified on magnetic resonance angiography, which showed the SCA as the parent vessel. The parent vessel was trapped, and the aneurysm sac was excised via right temporal craniotomy. Pathological examination of the sac revealed a false aneurysm. The patient's outcome was excellent. The pathophysiology of traumatic aneurysm at such a location suggests that surgery may be the treatment of choice.