Background: The data regarding the perception and practices regarding diabetes among diabetics, their family members, and the general population is sparse in India, especially in recent decade Aims and objectives: This cross-sectional study was carried out to ascertain the perception and practices of diabetes mellitus and to find the incongruities that exist in knowledge between the diabetic patients, their family members and the general population. Material and Methods: A community-based cross-sectional study was conducted over 2 years across 3 centres. Data was collected using pretested structured face-to-face interviews after taking informed written consent, and respondents were selected via convenience sampling. A total of 4244 people were interviewed. The population was then divided into three groups’ people with diabetes, their family members and the general population Results: Only 51.8% of respondents had knowledge of diabetes, with glaring disparities between the three groups. Amongst the general population, only 27.4% had knowledge of diabetes. Similarly, the awareness of prevention, complications and risk factors of diabetes was much lower in the general population compared to diabetics and their families, and this group had a significantly lower composite knowledge score of diabetes. Conclusion; About half of the population studied was found to have inadequate knowledge of diabetes. Even amongst the diabetics and their families, the perception and practices were poor. A greater emphasis on the dissemination of community education regarding symptoms, prevention and risk factors for diabetes is necessary.