Objective Increased oxidative stress has been identified as a pathogenetic mechanism in female infertility. However, the effect of specific antioxidants, such as coenzyme Q 10 (CoQ 10 ), on the outcomes after assisted reproductive technologies (ART) has not been clarified. The aim of this study was to systematically review and meta-analyze the best available evidence regarding the effect of CoQ 10 supplementation on clinical pregnancy (CPR), live birth (LBR), and miscarriage rates (MR) compared with placebo or no-treatment in women with infertility undergoing ART. Methods A comprehensive literature search was conducted in PubMed (MEDLINE), Cochrane, and Scopus, from inception to March 2020. Data were expressed as odds ratio (OR) with 95% confidence intervals (CI). The I 2 index was employed for heterogeneity.Results Five randomized-controlled trials fulfilled eligibility criteria (449 infertile women; 215 in CoQ 10 group and 234 in placebo/no treatment group). Oral supplementation of CoQ 10 resulted in an increase of CPR when compared with placebo or no-treatment (28.8% vs. 14.1%, respectively; OR 2.44, 95% CI 1.30-4.59, p = 0.006; I 2 32%). This effect remained significant when women with poor ovarian response and polycystic ovarian syndrome were analyzed separately. No difference between groups was observed regarding LBR (OR 1.67, 95% CI 0.66-4.25, p = 0.28; I 2 34%) and MR (OR 0.61, 95% CI 0.13-2.81, p = 0.52; I 2 0%). Conclusions Oral supplementation of CoQ 10 may increase CPR when compared with placebo or no-treatment, in women with infertility undergoing ART procedures, without an effect on LBR or MR. Keywords Coenzyme Q 10 . CoQ 10 . Female infertility . Assisted reproduction . Pregnancy outcomes . Meta-analysis Abbreviations IVF In vitro fertilization ICSI Intracytoplasmic sperm injection hCG Human chorionic gonadotropin PCOS Polycystic ovary syndrome POR Poor ovarian response * Michail Chourdakis