The pathology of congenital hearing loss is as varied as the etiologies. Severe external ear anomalies, such as microtia, and middle ear defects have a significant incidence of accompanying inner ear aplasias, more often of the vestibular than of the cochlear end-organs. Classic inner ear aplasias are discussed, including Michel, Mondini, Alexander and Scheibe. A case illustrating close resemblance between a genetically induced Scheibe malformation and rubella inner ear deformities is present. A variety of ear disorders acquired during intrauterine or neonatal life, including cytomegalic inclusion disease, hypoxia, erythroblastosis fetalis and later-onset genetic disorders are also discussed. Illustrative case histories are presented as well as priorities for future investigations into the pathology of congenital and genetic hearing loss.