A healthy 23-year-old man suffered helmet-to-helmet collisions with an opponent during American football game twice within 3 days. He then experienced continuous vomiting and dizziness. Magnetic resonance imaging revealed acute infarction in the right cerebellar hemisphere, and magnetic resonance angiography revealed transient stenosis of the right superior cerebellar artery. Although minor head injury is not usually accompanied by complications, posttraumatic ischemic stroke has been reported on rare occasions. We report a case of cerebellar infarction after repeated sports-related minor head injuries in a young adult and discuss the etiology.