ObjectiveTo systematically review the efficacy and safety of CoQ10 for idiopathic oligoasthenoteratozoospermia (iOAT). MethodsWe searched databases including PubMed, EMbase, MEDLINE, The Cochrane Library, CBM, CNKI, VIP and WanFang Data from inception to May 31th 2016 for randomized controlled trials (RCTs) on CoQ10 in the treatment of iOAT. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.3 software. ResultsSeven RCTs involving 803 patients were included. The results of meta-analysis showed, compared with the control group, the CoQ10 group could significantly increase sperm concentration (MD=3.37, 95%CI 0.68 to 6.05, P=0.01), the number of A grade spermatozoa (MD=5.06, 95%CI 3.84 to 6.28, P < 0.000 01), the number of A+B grade spermatozoa (MD=7.72, 95%CI 4.19 to 11.26, P < 0.000 1), the rate of morphologically normal sperm (MD=1.89, 95%CI 0.63 to 3.16, P=0.003) and sperm coenzyme Q10 level (MD=40.02, 95%CI 24.73 to 55.31, P < 0.000 01), while not improve the levels of serum sex hormone (FSH: MD=–3.48, 95%CI –5.17 to –1.79, P < 0.000 1; LH: MD=–3.23, 95%CI –7.55 to 1.08, P=0.14; T: MD=0.45, 95%CI –3.31 to 4.20, P=0.82). No significant difference in adverse event was noted between two groups. ConclusionThe evidence suggests that CoQ10 as empiric medical therapy for iOAT with low non-serious adverse event associated, may improve sperm concentration and percent sperm motility. However, the strength of evidence is low due to high risk of bias of the included studies. More rigorous studies are needed to verify the above conclusion.