The objective of this study was to explore oral health-related behavior, how patients with diabetes differ from patients not diagnosed with diabetes in their oral health and whether oral health-related behavior moderates the oral health status of patients with diabetes.Survey and chart review data were collected from 448 patients (52% male, 48% female, average age: 57 years) of which 77 were diagnosed with diabetes (17%).Patients with diabetes had a higher percentage of teeth with mobility than those not diagnosed with diabetes (14% vs. 8%, p=0.023), as well as gingival recession (16% vs. 12%, p=0.035) and more teeth with recession in the esthetic zone (1.17 vs. 0.88, p=0.046). They also had more decayed, missing and filled surfaces due to caries (101 vs. 82, p<0.001) and more missing teeth due to caries (11 vs. 7, p<0.001). Patients with diabetes brushed and flossed less frequently. Patients with diabetes who did not brush regularly had poorer periodontal health (percentage of teeth with probing depth of <4 mm: 82% vs. 60%, p=0.039, 4 to 6 mm: 34% vs. 17%, p=0.059) and more caries (percentage of decayed teeth: 32% vs. 15%, p=0.033) than regularly brushing patients with diabetes.Educating patients with diabetes about the importance of good oral self care needs to become a priority for their oral health care providers.