Life expectancy for children with serious congenital heart defects has dramatically increased in recent years due to advances in medical and surgical care. Anatomic studies of temporal bones in patients with non-syndromic congenital heart disease have demonstrated a high incidence of middle and inner ear anomalies. Systematic study of auditory function in these patients has not been reported. Fifty children with serious congenital heart disease have been evaluated with otologic examination and auditory brainstem-evoked response (ABR) testing. The patients ranged in age from 3 days to 17 years-8 months. Eight patients had hearing loss and normal otologic examinations, 14 patients had hearing loss and associated otitis media with effusion, and 28 patients had normal hearing by ABR testing. These results show a high incidence (16%) of hearing loss not associated with otitis media with effusion in the study population. We suggest that children with serious congenital heart disease are at high risk for hearing loss. This patient group will benefit from early identification, and appropriate medical and audiologic management.