The reliability of brainstem evoked response audiometry (ERA) as an objective audiometric study was evaluated in long term follow-up infants with moderate to severe sensorineural hearing loss. None of the infants had either brain damage (cerebral palsy, mental retardation) or other severe complications (genetis diseases). The thresholds of ERA at 1kHz and 4kHz were measured in 234 infants below one year of age, from 1983 to 1990, in our hospital. These infants were followed-up to the age when conditioned oriented response audiometry (COR) and play audiometry could be conducted. Pure tone thresholds obtained by COR and play audiometry were compared with those of ERA. In addition, speech problems in these patients were evaluated. In all of those infants, hearing aids were fitted before one year of age to achive early habilitation. As a results, ERA was found to be a reliable and efficacious test for determining auditory thresholds, and providing hearing aids for early habilitation in one-year old infants with moderate to severe sensorineural hearing loss.