A National Survey of the Oral Health of School Children was implemented in 1986. A probability sample of approximately 52,000 school-aged children in Kindergarten through 12th grade was selected. Thirteen examiners were trained and calibrated by NIDR staff in criteria for measurement of coronal caries, periodontal disease, fluorosis and presence of lesions of the oral soft tissues. Dental exams on approximately 41,000 children were conducted during the 1986-1987 school year by the 13 dental teams. A questionnaire on use of smokeless tobacco and alcohol was also administered and a salivary sample was collected. The overall response rate for participation was 78%. Data processing of forms and questionnaires was done. Preliminary analysis of the national estimates of DMF permanent surfaces indicated a 37% change from mean DMFS estimates from a similar study conducted in 1979-80. There was a lower level of disease at every age. Mean DMFS was also lower in all regions of the country; however, there were still differences between regions as before. Approximately 50% of the children ages 5-17 were caries free in their permanent dentition. A monograph on dental caries prevalence is being prepared. Data analysis will continue during the coming year.