An acute ischemic stroke (AIS) is a serious issue that affects people worldwide. It is the second most common reason for people deaths and the fourth main reason for people becoming disabled all around the world. Diabetes mellitus leads to increased platelet size and reactivity thereby, leading to higher Mean Platelet Volume (MPV) which plays a key part in atherosclerosis. Thus, this study was conducted to determine whether patients with diabetes mellitus had increased MPV value which contributes as a risk factor for acute ischemic stroke in these patients. Present study was a case-control study conducted on 100 patients (50 diabetic and 50 non diabetic) admitted with AIS. In the Diabetic group the mean HbA1c level was 7.67 ± 2.07 and in nondiabetic group the mean HbA1c level was 5.47 ± 1.64. The HbA1c level was significantly higher in Diabetic group (‘p’ <0.0001). The mean platelet volume was 10.17 (± 1.13) in Diabetic group whereas in non-diabetic group the mean platelet volume was 8.65 (± 0.96). The mean platelet volume was higher in Diabetic group (case) as compared to non-diabetic group (control) [‘p’ <0.0001].