The present investigation was performed in order to evaluate the use and benefit of in-the-ear hearing aids (ITE-HAs) after a 4-year observation period, and to examine the validity of this type of hearing aid. A sample of 537 subjects still in possession of ITE-HAs, fitted in 1985, responded to a postal questionnaire in 1989, including questions identical to the first follow-up in 1985. The 537 persons correspond to 60% of the originally fitted sample of 894 subjects. The investigation indicated that no change in the use of or benefit from ITE-HAs has taken place during a 4-year period, and in addition the manipulative skills of the hearing aid users did not improve. However, the overall frequency of handling problems is low, though with a tendency to increase in the age group above 75 years. It is concluded that the use of and benefit obtained with ITE-HAs remains unchanged over a 4-year period; that the use and benefit is similar in the age groups below and above 75 years of age; that the ITE-HAs seem to be fairly stable during a 4-year period.