Purpose: To evaluate the relationship between decayed, missing and filled teeth (DMF index) and body mass index (BMI). Materials and Methods: This was a cross-sectional, population-based study developed in 2015 at a primary health care (PHC) unit in the city of Sao Paulo, Brazil. Participants completed a form including sociodemographic and socioeconomic characteristics, nutritional, general health and oral health data. An anthropometric oral assessment was performed, and the association of DMFT and its components with not-categorised and categorised BMI was tested through simple and multiple logistic analysis, trend test and Spearman correlation. Results: The sample consisted of 239 individuals aged 18 to 70 years. The prevalence of caries was 84.5%, the mean DMFT was 14.6 and the mean BMI was 27.46. There was positive association for DMFT with BMI and age, sex, formal education, hypertension, diabetes and use of dental floss. A positive association is also suggested between BMI and missing teeth. Conclusion: A correlation was observed between DMFT (missing teeth) and BMI. This can help to identify at-risk groups, plan progammes and treatment of overweight and obese individuals in primary health care. Keywords: body mass index, DMF index, obesity, oral health, overweight, primary health care