Background: Dental caries is oral and dental disease that is mostly suffered by Indonesian. Dental caries is disease on the hard tissue of the tooth which begins with demineralization. The demineralization destructs the organic material that can cause pain. School period is the most vulnerable time for caries to occur. Objective: The purpose of this study was to determine the relationship between oral and dental knowledge with caries severity in children aged 8-10 years old. Method: The research was observational analytic study with cross sectional design. Fourty eight subjects were taken by random sampling technique. The subjects were given question from about oral and dental health. Caries Severity Index (CSI) was used to measure the level of caries severity. Result: The data was analyzed by using Spearman correlation test. Conclusion: There is no significant correlation (p>0.05) between oral and dental health knowledge and caries severity in children aged 8-10 years old.