A retrospective review of 168 consecutive children with congenital or early-onset bilateral hearing impairment (> 25 dB, 0.5-4 kHz, in the better hearing ear) was conducted. Only 39 per cent of the hearing-impaired children were diagnosed within the first two years of life. The age at diagnosis was related to the severity of hearing loss with profound (> 95 dB) hearing losses being detected earlier than the other degrees. However, 37 per cent of children with severe to profound (> 70 dB) hearing loss were still not diagnosed until after two years of age. Children with severe to profound hearing loss and with known risk factors were diagnosed earlier than children with the same hearing status but with no known risk factors. It was concluded that the behavioural hearing screening tests used in our well-baby clinics are insufficient and, therefore, more reliable methods, preferably evoked otoacoustic emissions, should be used for universal hearing screening of infants and young children in spite of the great cost.