Background: Problem of obesity is growing as pandemic around the world. Recent studies have investigated the role of vitamin D and obesity but found conflicting results. The aim of this present study is to examine the relationship between serum 25-hydroxy vitamin D3 levelswith Body mass index (BMI). Methods: In this cross-sectional study, a total no of 141 patients aged 19-70 years were enrolled for analysis. A complete history and physical examination was done and serum vitamin D levels were measured. Results: There were 54 men with age (Mean±SD) 36.6 ± 14.06 years and 87 women with age (Mean±SD) 35.72±12.28years. There were 19.1% overweight and 10.6% participants had obesity. Regarding serum vitamin D status among males and females, 87.1% of men and 93.1% of women and have serum vitamin D levels less than 30ng/ml. Whereas, patients with BMI (<25) had 5.4%and 86.8% deficiency and insufficiency respectively. Overweight and obese patients had 6.6%vs7.4%and 80%vs77.7% had deficiency and insufficiency, respectively. A significant inverse association was found between serum 25-hydroxy vitamin D3levels and BMI(p<0.05). Conclusion: In the present study, we concluded that serum 25-hydroxy vitamin D3levels had inverse significant correlation with body mass index