According to the recommendations of the National Board of Health in Finland fluoride tablets should be used daily from the age of 6 months to 15 yr in fluoride deficient areas. Topical fluorides are recommended in addition to systemic fluorides. The aim of this study was to analyze the use of fluoride tablets and topical fluorides by Finnish adolescents. Teenagers (n = 4705) representing Finnish youth aged 12, 14, 16 and 18 yr were sent mail questionnaires in February 1981. The response rate was 88%. The proportion of daily fluoride tablet users was 12% among 12-yr-old girls, 3% among 14-yr-old girls and among boys 10% and 4%, respectively. Fluoride rinses at home were used daily by only 1%. During the most recent school term, 34% had several times, and 8% once, participated in classroom fluoride rinsing. In the same period 14% had used fluoride gel several times, and 10% once. Thus despite dental health education, fluoride tablets and rinses are used very rarely at home by Finnish teenagers. The recommendations of the National Board of Health are far removed from the behavior of adolescents. Use of fluoride tablets and topical fluorides do not seem to be a practical alternative to drinking-water fluoridation, because of the low level of compliance.