The purpose of this study was to assess the knowledge diabetic patients have their risk of periodontal disease, their attitude towards oral health and their oral health related quality of life (OHRQL). One hundred and one consecutive patients (age 31-79 years), recruited from a diabetes clinic participated in the study. Twenty-seven percent of participants had type 1 diabetes, 66% type 2 and 7% do not know what kind of diabetes they had. The length of time since the participants were diagnosed as diabetics ranged from 1 to 48 years. Metabolic control of diabetes, as determined by HbA1c levels ranged from 6.2% to 12.0% compared to the normal range of 4, 5-6, 0%. Thirty-three percent of participants were aware of their increased risk of periodontal disease, 84% of their increased risk of heart disease, 98% for eye disease, 99% for circulatory problems and 94% for kidney disease. Half of the participants who were aware of their increased risk of periodontal disease have received this information from a dentist. Dental presence has been sporadic, with 43% reporting participation in recent years. OHRQL was not significantly influenced by the presence of diabetes in the group surveyed, compared with a previous investigation of non-diabetic patients. A significant association was found between metabolic control and dentate status. Awareness of the potential associations between diabetes, oral health and general health should be increased in diabetic patients.