Introduction: Dental caries or tooth cavities are the highest cause of dental and oral disease in Indonesia. Dental caries can occur in all age groups, including children, and it is feared that it can interfere their activities at school. Objective: This study aims to determine the relationship between oral health knowledge and behaviour with dental caries in 12-year-old children. Methods: This study requires 4 databases to collect articles, such as Scopus, Science Direct, Taylor & Francis, and JSTOR. Article searches were carried out based on keywords: “12 years old”, “Oral Health Knowledge”, “Behaviour”, “Dental Caries”, and “DMF-T Index”. In total, 338 articles were found and there were 6 articles reviewed. The method used in this study is a systematic review with the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). Results: Based on the results, the dental caries experiences are found in the 12-year-old children. From the quantitative study, it was found that knowledge and behaviour regarding oral health hold an important role in the occurrence of caries. There are multiple factors that impact on someone’s knowledge and behaviour. Conclusion: There is a positive relationship between oral health knowledge and behaviour with dental caries in 12-year-old children. Further research is needed on the determinants of knowledge and behavior that affect caries in children. © 2023 MPPKI. All rights reserved.