Eight children (ages 13 days to 5 years) with a diagnosis of Cornelia de Lange syndrome received audiologic evaluation consisting of immittance audiometry and auditory brainstem response audiometry to air and bone conducted "click" stimuli, as behavioral testing was unreliable due to patient age and/or developmental delay. Developmental assessments were also carried out on five of the children. Results indicated that all eight children had hearing sensitivity loss ranging from mild to severe and of varied site-of-lesion. Four children with mild conductive hearing loss had a history of chronic otitis media and were subsequently managed with pressure equalization tube placement and/or medication. Three with moderate to severe mixed or sensori-neural hearing loss required hearing aid fitting and special educational placement. The remaining child expired shortly after birth. Results of the developmental assessments found that four of the five children were characterized by severe to profound mental and motor delays. Data showed no relationship between the degree of developmental delay and the presence or absence of a significant hearing sensitivity loss. Case studies of two of the children are presented. (Seven references and 10 tables/figures) (JDD)