Objective: Although numerous studies demonstrate the link between vitamin D and its anti-inflammatory effects, the correlations could not be fully explained. Platelet-lymphocyte ratio (PLR) and neutrophil-lymphocyte ratio (NLR) are investigated as biomarkers for diagnosis and follow-up in various obstetrics and gynecological studies. We aimed to evaluate the correlation between the anti-inflammatory effect of vitamin D and inflammatory parameters NLR and PLR in women with polycystic ovary syndrome (PCOS) and endometriosis.Materials and Methods: Serum 25-hydroxy vitamin D (25(OH)D) levels, complete blood count (CBC) parameters, NLR, PLR, Vitamin B12, and thyroid stimulating hormone (TSH) levels of 140 patients who applied to the Department of Obstetrics and Gynecology between 2010-2019 were evaluated. In our study, the levels of 25(OH)D, TSH, vitamin B12 and CBC measurements were analyzed simultaneously. SPSS 22.0 Windows version software was utilized in the data analysis, and p<0.05 was accepted as statistical significance level.Results: There were significant differences in NLR (p=0.026) and lymphocytes count between PCOS and endometriosis groups (p=0.010). When we examined PCOS and endometriosis patients as a patient group; according to 25(OH)D vitamin levels, we found that NLR was significantly higher in the group with 25(OH)D vitamin levels below 20 ng/ml (p=0.017), vit B12 levels were significantly lower (p=0.034). Bivariate correlation analysis showed that vitamin D was negatively correlated with NLR (r=-0.196, p=0.050) in the patients with PCOS but not with endometriosis.Conclusion: This retrospective study assessed the association between vitamin D levels and the new inflammation biomarkers in patients with PCOS and endometriosis. The CBC and neutrophil/lymphocyte ratios are accessible and easily measurable biomarkers, therefore, evaluating the anti-inflammatory effect of vitamin D together with NLR is valuable for both PCOS and endometriosis.