Introduction and aim. Diabetes mellitus (DM) is a basic metabolic disease of inadequate control of blood glucose levels. Hyperglycemia is exacerbated, and type 2 diabetes mellitus (T2DM) progresses both insulin resistance and β-cell dysfunction. Management of T2DM involves both lifestyle modification and pharmacological therapy. To achieve optimized health outcomes, the patient requires adequate knowledge, attitude, and practice, so educating the patients on these diseases is an effective strategy to reduce complications of T2DM. Material and methods. This is a cross-sectional study which was conducted from August 2022 to January 2023. A total of 200 participants were enrolled with inclusion criteria to determine the knowledge, attitude, and practice of type 2 diabetes mellitus patients. Results. The mean knowledge, attitude and practice (KAP) was 71.5%, 87.5%, and 40% respectively. There is a significant association between knowledge, attitude, practice questions, and socio-demographic characteristics. Education was strongly associated with having higher knowledge scores (p=0.001). Conclusion. The study’s conclusions made clear the necessity of well-planned interventions to raise T2DM awareness among patients with low levels of education. Patients with T2DM may benefit from well-designed educational programs that encourage healthy behavior and these interventions can improve the quality of life of patients in rural region of Tamil Nadu.