RESULTS of studies of children with hearing problems thought to be etiologically related to hemolytic disease of the newborn (HDN) have varied widely. Cavanaugh1 reported an incidence as low as 4%; Crabtree and Gerrard,2 80%. Good-hill3 reporting from this institution found hearing loss in two of 15 children known to have had HDN; both had cerebral palsy. He subsequently distributed a questionnaire to a school for the deaf and found that, among children with a history of HDN who did not have cerebral palsy, the incidence of hearing loss was low. Phelps4 described the hearing loss as being of a kind peculiar to children with athetoid cerebral palsy. Rosen5 found that the hearing loss fluctuated, which made diagnosis difficult; and Myklebust6 was of the opinion that aphasia or deafness or both might be present. The studies reviewed had the following two factors in common: