A 43-year-old corrections officer developed right neck and posterior head pain following a karate punch to the right side of the neck during self-defense training. One week later, he developed an acute left hemiparesis. Magnetic resonance imaging demonstrated a right hemisphere cerebral infarction and absence of signal flow void in the right internal carotid artery. Carotid ultrasound demonstrated complete occlusion of the right internal carotid artery without evidence of atherosclerotic disease. Carotid occlusion with cerebrovascular infarction is a possible complication of martial arts training involving forceful blows to the neck.