Several days after receiving a blow to the occipital region, a 5-year-old boy presented with acute symptoms and signs of a space-occupying-lesion in the posterior fossa. A CAT scan revealed a mass with increased density in the region of the fourth ventricle. A suboccipital craniectomy disclosed a subependymal hematoma bulging into the fourth ventricle. The hematoma was evacuated, and the child subsequently made a complete recovery. It is stressed that surgical intervention should be considered in all such cases and particularly in young patients who show progressive neurological deficits.