MR analysis identified associations of CCL28 (OR = 0.781, 95% CI: 0.615–0.993, P = .044), interleukin-18 (OR = 0.824, 95% CI: 0.723–0.940, P = .004), and RANTES (OR = 0.797, 95% CI: 0.669–0.949, P = .011) with PCOS risk. This evidence concerns the gene CCL5 and polycystic ovary syndrome.