ABSTRACT Background: Dental caries and periodontal disease are global problems and can occur at any age, including children. Dental and oral hygiene and children’s diet are the main risk factors for periodontal and caries disease. In preschoolers, parents, especially mothers, dominate diet choices and oral hygiene behavior. The level of education, knowledge, and socioeconomic status will affect the mother’s attitude towards the child’s dental and oral health. Purpose: This study aims to determine the relationship between education and knowledge of mothers to caries and periodontal status of children aged 3-6 years. Methods: This study was an observational cross-sectional analytic study with simple random sampling conducted at Balai RW 3 Sidotopo, Semampir district, Surabaya in July to August 2018. There were 110 mothers and children as respondents. The level of education and knowledge of mothers were measured through questionnaires, while the caries and periodontal status of children were measured using the DMF-T and WHO examination. The obtained data were then analyzed by Spearman correlation test. Results: Statistical results showed that there was a significant relationship between income and caries status of children, but there was no relationship between education and mother’s knowledge of child caries. Education, knowledge, and income are also not related to the child’s periodontal status. Conclusion: There is no relationship between education and mother’s knowledge on child caries, but there is a significant relationship between income and caries status of children. While, there is no relationship between education, knowledge, and income on the child’s periodontal status.