Purpose: The first large-scale epidemiological survey on dental caries in the Republic of Slovenia was conducted in 1987 and repeated in 1993, 1998, 2003, 2008 and 2013, using the same methodology. The aim of the study was to describe the trend of caries in 12-year-olds in Slovenia from 1987 to 2013. Materials and Methods: The method applied in all six surveys was the National Oral Pathfinder Survey using WHO combined oral health and treatment need assessment forms. The surveys were performed in ten towns in all nine geographical regions of Slovenia. One randomly selected primary school in each town participated in the surveys. In each subject selected from the respective class of 12-year-old children, the caries experience and sealant data were recorded, using artificial light, a plane mirror and a sharp explorer. For statistical analysis of the results, the Statistical Package for Social Sciences (SPSS) was used. Results: The mean DMFT decreased significantly from 5.1 in 1987 to less than 1.7 in 2008 (p 0.0001), but afterwards began to increase and reached a mean value of almost 1.9 in 2013 (p > 0.05). The percentage of sealed teeth increased from 6% in 1987 to 92% in 2013. Conclusion: The substantial caries decline in 12-year-olds was evaluated as being due to the preventive measures implemented. However, in the last survey, the caries decline had stopped. Keywords: caries, children, DMFT, epidemiology, fissure sealing