Background: Hypovitaminosis D is associated with diabetes mellitus (DM). Aim of our study was to determine the relation of obesity with vitamin D levels in type 2 diabetic patients. Materials and Methods: We examined 101 type 2 diabetic patients and made a correlation analysis in all parameters. Then we classified our diabetics according to their body-mass indices and compared their 25 hdroxy vitamin D3 levels. Results: We found negative correlation between 25O HD and body mass index (BMI) (P: <0.001, r: -0.23). When we classified our diabetics according to their body mass indices as normal, overweight and obese, and compared their 25 hydroxy vitamin D3 levels, we determined that in every BMI group 25 hydroxy vitamin D levels were not found to be significantly different. Conclusion: These results suggest that at least in a Turkish population with type 2 DM vitamin D levels are low and correlate with BMI, but when vitamin D levels are so low, as obesity worsens vitamin D levels does not lessen.