Prospective screening of an extremely high risk group of 137 infants cared for in the Newborn Intensive Care Unit of the James Whitcomb Riley Hospital for Children was undertaken during 1983. Auditory brain stem responses (ABR) were obtained utilizing a clinical evoked potential system (Madsen 2250). Patients were selected for screening prior to discharge or transfer to the referring hospital on the basis of one or more of the following criteria: birth weight <1250 grams; birth weight <1500 grams and ventilatory support; significant depression at birth (Apgars <3 and 6 at 1 and 5 minutes, respectively); seizures, meningitis, and/or sepsis. Of the original 137 infants tested, 82 passed the initial ABR, 22 conditionally passed, and 34 failed. Eighty-two infants had follow-up behavioral and audiometric testing while 20 infants died and 35 were lost to follow-up. Four infants had severe sensorineural hearing loss, each of whom had failed the initial ABR. None of the infants who initially passed or conditionally passed the ABR had sensorineural hearing loss on followup testing. High risk factors for sensorineural hearing loss in the neonatal period included: intraventricular/periventricular hemorrhage, apnea, family history, major malformations of the head and neck, and possibly hyperbilirubinemia and congenital infection. No relationship of sensorineural hearing loss with very low birth weight, hyponatremia, infection, seizures, or medications was found. On the basis of these data, it is suggested that electrophysiologic hearing screening of a high risk population may be delayed until 3 to 6 months of age to improve specificity of testing.