Objective: This research was conducted to assess the effects of coenzyme Q10 (CoQ10) intake on gene expression related to insulin, lipid and inflammation in subjects with polycystic ovary syndrome (PCOS). Methods: This randomized double-blind, placebo-controlled trial was conducted on 40 subjects diagnosed with PCOS. Subjects were randomly allocated into two groups to intake either 100 mg CoQ10 (n ¼ 20) or placebo (n ¼ 20) per day for 12 weeks. Gene expression related to insulin, lipid and inflammation were quantified in blood samples of PCOS women with RT-PCR method.