Among 135,000 patients admitted to a hospital and clinic in a large, rural area, 296 underwent roentgenographic examination of the skull because of injuries to the back of the head. A fracture of the occipital bone was found in 98 patients, 32 of whom had severe complications. The 21 cases here described involved lesions in the posterior fossa and included 2 fatal cases of intracerebellar hemorrhage. There were eight cases of extradural hemorrhage in this region; decompression or removal of clots was followed by complete recovery in seven of these. The eighth was not relieved by making a bur hole in the occipital region; he died following a lumbar puncture, and autopsy revealed both an extradural hemorrhage and a bilateral subdural hematoma. Subdural hematoma was found in four patients, three of whom died; it is believed that all might have been saved had bur holes been placed in both supratentorial and infratentorial regions. Subdural hygroma occurred in seven patients, and all survived; more rapid improvement resulted from the making of bur holes into the posterior fossa to permit the escape of trapped cerebrospinal fluid and to reduce the intracranial pressure. In the past, attention has been focused on lesions to the surface of the cerebral hemispheres; these cases show that similar attention should be given to the structures in the posterior fossa.