['To investigate the relationship between mean platelet volume (MPV) and glycometabolic indices, to compare MPV according to HbA1c levels, and to analyse the difference in MPV between patients with and without microvascular complications.', 'This retrospective study was conducted on 60 Type 2 diabetic patients and 50 age- and sex-matched non-diabetic controls. We obtained demographic, clinical and laboratory data including MPV, platelet count, fasting and postprandial blood glucose (FBG and PBG), haemoglobin A1c (HbA1c), lipid profile, creatinine, systolic and diastolic blood pressure (BP) in patient and control groups, and diabetic microvascular complications including nephropathy, neuropathy, and retinopathy in the patient group. All analyses were performed using SPSS version 15.0 for Windows.', 'Mean platelet volume in the diabetic group was higher than in the control group (p = 0.001). Mean platelet volume was positively correlated with FBG and HbA1c levels (p = 0.03 and p < 0.001, respectively). It was also negatively related to platelet count (p < 0.001). Mean platelet volume in patients with HbA1c > 7% was significantly higher than those with HbA1c ≤ 7% (p < 0.001). Mean platelet volume was significantly increased in patients with retinopathy compared to those without retinopathy (p = 0.04).'] Is mean platelet volume associated with glycaemic control and retinopathy in patients with type 2 diabetes mellitus?