Aim: The aim of this study was to establish the caries prevalence and the connection between the recorded resultsand the known risk factors for caries development, on the sample of schoolchildren from rural and urban areas of Croatia. The purpose was also to analyse the differences in caries prevalence in different regions of Croatia and the connection of oral health to socioeconomic status (SES) and to dietary and hygiene habits. Subjects and methods: The study included 1874 elementary schoolchildren in rural and urban areas of Croatia: Štitar and Babina Greda (rural population) as well as Županja, Zagreb and Dubrovnik (urban population). Children’s teeth were examined under standardized conditions using visual-tactile method and their oral health status was recorded, according to the World Health Organization (WHO) criteria. The dmft/DMFT, dmfs/DMFS and SiC indexes were calculated and the analysis of the filled questionnaires was done. Results: Caries prevalence of all schoolchildren was 50,0%, of which 70,2% was from rural and 46% from urban areas. Median DMFT of all schoolchildren was 2, in rural area it was 4 and in urban area it was 2 (p<0,001). Considering regions, median DMFT for Slavonia was 3, and for both Zagreb and Dubrovnik it was 1 (p<0,001). The mean DMFT for all 12-year-olds was 3,4 whilst median DMFT was 4 in rural and 3 in urban areas. There was a statistically significant difference between younger (6–10 years of age) and older (11–16 years of age) schoolchildren, where DMFT and DMFS indexes of latter were significantly higher (p<0,001). Median SiC index of all schoolchildren was 4; in rural areas was 4 and in urban areas was 4. Median dmft of all schoolchildren was 1 and the highest median dmft score was found in 6-year-olds (it was 9 in rural and 7 in urban areas). The questionnaire analysis showed positive and statistically highly significant interconnection between SES and the frequency of tooth brushing as well as between SES and oral hygiene level. That interconnection was found in younger and older schoolchildren groups, as well as in younger schoolchildren's parents. The simple linear regression analysis showed a weak and negative, statistically significant interconnection between SES and oral health status of younger (6-10 years of age) and older (11-16 years of age) schoolchildren. Conclusion: The study results showed high caries prevalence of 50% among schoolchildren in primary schools in investigated parts of Croatia. Schoolchildren in investigated rural and urban areas of Croatia fall into moderate to high DMFT group, according to WHO classification of DMFT. Those results indicate the need for a comprehensive epidemiological research involving all areas of Croatia which could help in setting goals for necessary preventive programmes and curative care. Only SES, of all investigated caries risk factors, showed the influence on the oral health of the examinees, the higher the SES, the higher was the oral health. In conclusion, there is a need for good preventive strategy, a systematic education of the parents, children, dental medicine doctors and entire population on the importance of oral health and caries prevention as well as on the necessity of preventive programmes implementation.