Although, the value of I2 = 63% (I2 > 50, P < 0.01), indicating that there existed moderate heterogeneity so we performed the subgroup analysis to found the sources of heterogeneity so the meta-analysis results of our study could serve as the relationship between PCOS and serum PSA levels in PCOS patients. This evidence concerns the gene KLK3 and polycystic ovary syndrome.