In order to determine whether children screened 6-12 months previously for vision and hearing had fewer vision and hearing problems than a non-screened cohort, a trained nurse-tester examined 763 screened and 743 non-screened kindergarten children matched for age, sex, and socioeconomic status. The screened cohort had significantly fewer vision problems (10%) than the unscreened (15%). The difference for moderately severe problems (visual activity 20/50 or worse) was also significant. 58% more screened than unscreened children were wearing glasses. The screened cohort had more hearing problems (16.8%) than the non-screened group (14%), but the difference was not statistically significant. There was a marked seasonal variation in prevalence of hearing problems, the frequency in November and December being twice that in April, presumably a result of increased frequency of upper respiratory problems in those months. Preschool hearing screening, unlike vision screening, is not associated with improved end results.