Diabetes mellitus (DM) is a disease that is characterized by hyperglycemia, a condition where blood glucose level is higher than normal. Recent researches have shown that tooth brushing frequency is a potential risk factor for DM. Indonesian Basic Health Research (Riskesdas) collected the data of tooth brushing behavior of Indonesian people in 2018 according to the time of the tooth brushing. The data showed that the majority of Indonesian people brushed their teeth every day, but only 2.8 % of them did it at the right time. This problem might have an association with DM occurrence in Indonesia. This study aimed to analyze the tooth brushing behavior and DM occurrence association in Indonesia using the Indonesian Basic Health Research 2018 data. This cross-sectional study used a total of 455,040 interviewed respondents aged 30-80 years old that had complete data of their daily tooth brushing behavior. Tooth brushing behavior was the main independent variable. Other independent variables were age, sex, sweet drinks consumption, sweet foods consumption, fatty foods consumption, fruits and vegetables consumption, physical activity, and obesity. The dependent variable was the occurrence of DM based on diagnosis by doctor.