Objective: Our study sought to evaluate the association between periodontitis and body mass index (BMI) among patients with type 2 diabetes mellitus. Methods: In this cross-sectional case control study analysis of 186 diabetic patients, 112 patients had a body mass index >30kg/m2 and 74 control patients had BMI <30kg/m2. All participants underwent oral examinations including a full mouth recording of clinical attachment level (CAL). Information regarding HbA1c levels and high-sensitivity C-reactive protein (hs-CRP) were also gathered. Results: Over half (61%) of patients had a BMI >30. Of these 52% had CAL less than 2mm. Multivariate logistic regression analysis showed that there was no association between BMI and CAL. In addition, hs-CRP levels were significantly and positively associated with CAL (OR:1.06, 95% CI: 1.01, 1.12; p=0.007). Conclusion: Among patients with type 2 diabetes mellitus, there was no association between periodontitis and BMI. More studies are needed to further explore this relationship taking into consideration additional lifestyle factors.