Background: Polycystic ovary syndrome (PCOS) is enigma faced by young females since the onset of urbanization. As on day, PCOS is the most common endocrine disorder in the women of reproductive age affecting 4-10%. This study done to measure serum vitamin D3 levels of PCOS patients and to identify its association with factors associated with various symptoms and signs in PCOS.Methods: Institutional based prospective observational study conducted on 70 patients of PCOS, both suspected and already diagnosed, attending gynecology OPD of Department of obstetrics and gynecology of NSCB Medical College Jabalpur from 1 March 2015 to 31 August 2016. Diagnosis of PCOS was made by Rotterdam 2003 criteria. A detailed assessment was done and preformed proforma was filled. Serum Vitamin D3 levels were estimated by standard lab technique ‘Liquid Chromatography Tandem Mass Spectrometry’ and categorized into vitamin D3 sufficient >30ng/dl, insufficient 20-29ng/dl and deficient <20ng/dl. Categorical data was coded numerically before the analysis. For comparison of frequency distribution chi square test or fisher’s exact test were applied as appropriate.Results: Prevalence of Vitamin D3 deficiency in patients of PCOS was found to be 84.3%.Conclusions: The present study concludes that there is correlation between vitamin D3 and PCOS, screening and correction of vitamin D3 deficiency may prevent PCOS and its manifestations. Hence, it is speculated that improvement of vitamin D3 levels at a younger age can contribute to prevention of PCOS.