Objective To systematically review the association between 5α-reductase inhibitors (5ARIs) and risk of sexual dysfunction in subjects with benign prostatic hyperplasia (BPH).Methods PubMed, Web of Science, The Cochrane Library, EMbase, CNKI, WanFang Data, VIP and CBM databases were electronically searched to collect the randomized controlled trials (RCTs) on the association between 5ARIs and risk of sexual dysfunction in subjects with BPH from inception to October 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 12.0 software.Results A total of 15 RCTs involving 17 774 subjects were included. The results of meta-analysis showed that, compared with the placebo group, 5ARIs could significantly increase the risk of erectile dysfunction (RR=1.52, 95%CI 1.36 to 1.69, P<0.000 1), decreased libido (RR=1.79, 95%CI 1.37 to 2.32, P<0.000 1) and ejaculation disorder (RR=2.97, 95%CI 1.82 to 4.83, P<0.000 1) in subjects with BPH. The results of subgroup analysis showed that the type of 5ARIs, intervention period, and publication year and sample size had a higher risk of sexual dysfunction than the placebo group.Conclusion Current evidence shows that 5ARIs can increase the risk of erectile dysfunction, decreased libido and ejaculation disorder in subjects with BPH. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusion.