• Among the hereditary affections of the nervous system associated with deafness, a rare condition called "progressive pontobulbar palsy with deafness" has been described. In this slowly progressive condition, hearing loss and vestibular areflexia are almost always the first symptoms, occurring in late childhood or early adulthood. Only 18 cases—some sporadic, several familial—have been published without a full report of pathological findings. The clinical and pathological data of two new cases—one familial, one sporadic—are described here. There are differences from other forms of bulbar paralysis, lower motor neuron diseases, and some spinocerebellar hereditary affections. In view of the homochrony and homotypy in familial cases and the pathological findings, progressive pontobulbar palsy with deafness appears to be an abiotrophic process with autosomal recessive inheritance.