ABSTRACTNeurological symptoms in achondroplasia are described and discussed on the basis of two cases. In one case there was a congenital hydrocephalus, probably caused by changes of the bones at the base of the skull and pronounced basilar impression. Before puberty the patient had repeated acute attacks of increased intracranial pressure, provoked by slight head injuries and infections. After puberty a slowly progressive spastic paraparesis developed, combined with peripheral symptoms. Gas myelography revealed a very narrow subarachnoid space. In the second case a rapidly progressive bilateral lumbosacral rhizopathy developed at the age of 50 years, and oil myelography showed a total lumbar block. The technique of myelography and the types of therapy in achondroplasia are discussed.