Screening for hearing loss in the first year of life, using the distraction test, remains the responsibility of health visitors in most health districts in the United Kingdom. We have evaluated the screening procedure used routinely in one health region in a population of infants at increased risk of sensorineural deafness. They were infants who weighed less than 2000 g at birth or infants who weighed 2000 g or more at birth and who spent more than 24 hours in a special care nursery. The infants' responses to a distraction test were recorded by health visitors and sent to the project office. The results were compared with information from a regional register of early childhood impairment that included children in whom sensorineural deafness had been diagnosed before the age of 3 years. The register had been compiled using information from a wide range of sources. When used in this high risk population the distraction test was sensitive (91%), but nonspecific (82%). The effectiveness of the screening programme was limited, however, because there was an increased risk of deafness among infants who missed being screened by health visitors. In addition, 71% of the deaf infants on the register were not in the high risk population.