A comprehensive systematic preventive dental health program was implemented in a young population with Down's Syndrome during a 30‐month period. Twenty children (nine boys and 11 girls), ages 8–13 (mean age, 11), participated in the study, which took place in three hostel‐like apartments. The main goals of this program were to achieve good plaque control and subsequently prevent periodontal disease as well as to apply fissure sealants and fluorides in an attempt to prevent dental caries. The mean plaque and gingival indices as well as the percentage of bleeding sites decreased significantly (p<0.01) following the administration of our oral health program. Caries experience, as indicated by DMFS, decreased from 1.35 to 1.05 surfacesperchild, and the use of fissure sealants to prevent occlusal caries was proved to be 100% effective. It is concluded that if the children's efforts are integrated with those of a motivated dentist, dental hygienist, and staff, a well‐planned preventive dental health program can lead to a high degree of success in the prevention of dental diseases in young populations with Down's S