The purpose of the present study was to determine whether the caries-preventive effect of school-based programs with fluoride (F) mouthrinsing or toothbrushing was evident at the end of a post-treatment follow-up period of 11 years. Two groups of subjects examined at 14 years of age (born in 1960), who had participated in fortnightly F rinsing (n = 52) or in F brushing 4-5 times a year at school (n = 50), were re-examined radiographically and completed a questionnaire at age 25 years. A comparison group of 25-year-olds (n = 51) was also included. Analyses of variance showed that the benefits of participation in school-based F programs seem to have been lost. It appears that these caries-preventive programs have delayed rather than prevented caries and that F toothpaste and other caries-preventive efforts have been insufficient to avert a substantial caries activity during the follow-up period.