India has the second largest concentration of tribal population in the world. Indian tribes constitute around 8.3% of nation’s total population. To assess the prevalence of Prediabetes and diabetes mellitus among tribal population of Kancheepuram district. Cross sectional study design, Multi stage cluster sampling technique was used, house to house data collection was done for 85 irula tribal people. The Irula are a Scheduled tribe that lives in northern Tamil Nadu and the Nilgiri Hills. They are sort of like a cross between tribals and ordinary southern Indians. structured questionnaire were used to assess demographic variables (gender, age, educational qualification, marital status, family status, occupation, monthly salary and religion). Measurements taken were height, weight, and blood sugar by finger prick method with glucometer. Above 140 to 199 mg/dl considered as prediabetes and 200mg/dl is considered as diabetes. Prevalence of prediabetes and diabetes mellitus among tribes were 49.4%, 25.9%, poor literacy, poverty and substance abuse makes the tribes more prone to prediabetes and diabetes.