INTRODUCTION: Diabetes Mellitus (DM) poses a global health challenge, representing a pandemic issue. It is recognized as a condition that increases the likelihood of blood clot formation, leading to heightened platelet activity. Elevated platelet activation can induce c hanges in platelet morphology and function, contributing to the onset of both microvascular and macrovascular complications in individuals with this metabolic condition. Despite being readily available, platelet indices such as Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), and Plateletcrit (PCT) remain underused in clinical laboratory settings. Elevated levels of the AST to Platelet Ratio Index (APRI) show a significant correlation with Cardiovascular Risk (CVR), indicating a substantial in crease in CVR, warranting attention and monitoring. M ATERIALS AND METHOD A cross sectional investigation took place at the Department of Pathology, Chettinad Hospital and Research Institute, Chengalpattu, spanning three months from February 2023. The study examined 144 patients with Type 2 Diabetes Mellitus (DM) who were receiving care at the Outpatient Department (OPD). RESULTS: Among the 144 patients, 68% (98 individuals) suffered from diabetic complications, with 32% (46 out of 98) experiencing cardiovas cular issues. Notably, patients with nephropathy demonstrated higher MPV and platelet levels, while those with retinopathy had elevated PDW. Furthermore, patients with cardiovascular complications exhibited increased Plateletcrit and HbA1c levels.A compari son between patients with and without diabetic complications revealed significant differences in age, duration of diabetes, Fasting Blood Sugar (FBS), HbA1c, MPV, and PDW. Additionally, when platelet indices were compared with glycaemic control, patients w ith poorly managed diabetes displayed higher platelet indices compared to those with controlled diabetes, with statistical significance.Moreover, a positive and significant correlation was observed between MPV, PDW, APRI, duration of diabetes, FBS, HbA1c, and diabetic complications, whereas a negative correlation was found with platelet count, all of which were statistically significant. CONCLUSION: Platelet Indices and APRI offer a straightforward and accessible approach to assessing platelet hyperactivity in Diabetes Mellitus (DM).