The otological, auditory and developmental effects of treatment with ventilation tubes were studied in a sample of 7-8-year-old Dutch children screened for otitis media with effusion (OME) serially at preschool age. Children treated with ventilation tubes were matched retrospectively for OME history, sex, and age with children who were not treated surgically. At the age of 7-8, abnormalities of the tympanic membrane were more prevalent in treated than in untreated ears. No significant differences were found in middle ear function and hearing in both groups. Some positive effects of early surgical intervention on specific developmental measures were found.