Objectives: To study the rate of dental caries and treatment demand in the 12 year old children. Research method: Cross-sectional description. Research venues: Elementary and junior high school in eight provinces/cities which have been selected for the program "school disease model investigation" of the Ministry of Health. Results: The rate of tooth decay in 12-year-old vietnamese children was high: the percentage of permanent tooth caries was 51.2 percent, the DMFT index was 1.49. The caries treatment demand for 12 years old children was high: the proportion of untreated dental caries at that ages was 85.9 percent, the proportion of filled dental caries was 10.1 percent. Demand in dental caries treatment in 12 year - old Vietnamese children was high: 51.2 percent of children needed tooth restoration, 35,4 percent of students needed pit and fissure sealants, 25.3 percent of children needed re-mineralization treatment, 5, 1 percent of children needed tooth extraction, the other treatments (pulp treatment, tooth crown) contained 16,8 percent.