Fifty-two children who had deaf parents and were thought to have normal hearing were evaluated for speech, hearing, and language problems. Standardized tests, audiological evaluations, and informal conversation and play techniques were used. Of the 52 children of deaf parents, less than half were considered to be developing speech and language normally and 12% had previously undiagnosed hearing loss. The prevalence of speech and language problems and hearing losses is higher in this population than in the population at large. The children appeared to be using two systems to communicate, one with hearing people and one with the deaf. Of the children having some speech and language difficulty, approximately half had problems that were not associated with other known physiological or environmental factors that might affect speech and language. Although there were no children of intelligible mothers who had speech and language problems, there were children developing normally who had parents whose speech intelligibility was poor. Contrary to indications in the literature, speech and language problems did not disappear after the children entered school. A large number of school-age children as well as preschoolers appeared to be having speech and language problems. The amount of time spent with hearing adults during the preschool years or the presence of older normal-hearing and -speaking siblings did not seem related to speech and language difficulty. However, when an elder sibling had speech and language difficulty, the younger siblings tended to have similar problems. The relationship between sign and oral language development is ambiguous, but there is no indication that the use of sign language deters oral language development. In view of the high incidence of communication problems in this population, annual audiological evaluations and counseling of deaf parents concerning aspects of hearing loss and normal language development are recommended. The problems encountered in providing therapy are discussed.