A cerebral fat embolism is an uncommon but serious complication of long bone fracture. It can be fatal, and early detection is not easy. Neurologic symptoms are variable, and the clinical diagnosis is difficult. The pathogenesis remains controversial, and several theories have been proposed. Magnetic resonance imaging can detect a cerebral fat embolism with a higher sensitivity than cerebral computed tomography. We report a case of a posttraumatic cerebral fat embolism without pulmonary involvement and review the existing literature.