A survey was conducted of deaf children in the Glasgow area diagnosed between 1965 and 1979 to assess the relative incidences of the known aetiological factors. This took the form of a review of case records supplemented by the use of questionnaires. The results showed small variations from earlier published figures but were broadly similar. The effectiveness of rubella and anti-Rhesus immunization were also evaluated. It was found that more than half of all cases of profound deafness in childhood are acquired rather than inherited and are therefore potentially preventable