Vitamin D deficiency, increased platelet indices and abnormal lipid profile are closely associated with increased vascular complications in type 2 diabetes mellitus (T2DM) patients. We investigated the relationship between glycemic control and platelet indices, vitamin D, atherogenic index of plasma (AIP) and other lipid components in T2DM patients. Materials and Methods: Diabetic subjects were divided into the groups 1 (good glycemic control, n=59 patients), 2 (moderate glycemic control, n=71 patients), and 3 (poor glycemic control, n=95 patients) according to the HbA1c levels of <7%, 7-9%, and >9%, respectively. We retrospectively analyzed serum lipid profile, platelet count, platelet indices, calcium, phosphorus, vitamin D and HbA1c levels in all patients. The AIP values of the subjects were calculated as follows: AIP=[log triglyceride/high density lipoprotein cholesterol (HDLc)]. Results: In group 1, the mean platelet volume (MPV), platelet distribution width (PDW), platelet large cell ratio (P-LCR), triglyceride and AIP levels were lower, and the HDLc levels were higher than in group 3. Platelet indices, lipid profile, and AIP values of group 2 did not differ from those of group 1 or group 3. There was no difference among the three groups in terms of vitamin D levels. HBA1c levels were positively correlated with the duration of diabetes, triglycerides, AIP, PDW, MPV, and P-LCR, and negatively correlated with HDLc. Results: Increased platelet indices (MPV, PDW and P-LCR) and AIP values were observed in poor glycemic controlled diabetics. Accordingly, these parameters may be helpful in assessing increased cardiovascular risk in diabetics.