A case of a traumatic middle cerebral artery occlusion resulting from a boxing injury is presented. A 22-year-old man, an amateur boxer, was admitted because of difficulty in speaking, that had appeared a day after a sparring fight. A computed tomographic scan showed low-density areas in the left globus pallidus and corona radiata. A carotid angiogram indicated complete occlusion of the left middle cerebral artery at its origin and an irregularity and narrowing of the left internal carotid artery in its supraclinoid portion. The patient was discharged 4 weeks after the admission with some persistent expressive dysphasia that diminished during the next month. The clinical features and mechanisms of the traumatic middle cerebral artery occlusion are discussed.