A 31-year-old white man was found to have Brown's syndrome following severe closed-head injuries sustained in a motorcycle accident. Computed tomography scans revealed a displaced fracture of the right orbital roof, with entrapment of the superior oblique muscle. Surgical attempts to free the muscle were unsuccessful, so the superior oblique tendon was recessed 10 mm, and the inferior rectus was recessed on an adjustable suture. We believe this to be the first report of a case of entrapment producing an acquired Brown's syndrome and the first case of a motility disorder resulting from entrapment of an extraocular muscle in an orbital roof fracture.