Objectives: Erectile dysfunction is common after kidney transplant. The phosphodiesterase-5 inhibitors are the primary drugs for the treatment of erectile dysfunction. The purpose of this study was to evaluate the efficacy and safety of these drugs in the treatment of erectile dysfunction after kidney transplant. Materials and Methods: Randomized controlled trials were identified and extracted from MEDLINE, the Web of Science, Cochrane Central, and reference lists. The database search, quality assessment, and data extraction were performed independently by 2 reviewers. Eligible studies were randomized controlled trials and quasi-randomized controlled trials. Treatment efficacy was assessed with the International Index of Erectile Function score. Results: There were 3 studies identified that satisfied inclusion criteria. The International Index of Erectile Function score for phosphodiesterase-5 inhibitors increased ≥ 9 points compared with placebo (mean difference, 11.81; 95% confidence interval: 9.14-14.48; P < .00001). There were no differences between the phosphodiesterase-5 inhibitors and placebo in the incidence of adverse events, creatinine levels, or concentrations of cyclosporine or tacrolimus. Conclusions: Phosphodiesterase-5 inhibitors are effective and safe in treating erectile dysfunction after kidney transplant. Phosphodiesterase-5 inhibitors do not cause changes in kidney function or immunosuppressive drug concentrations after kidney transplant and may be used as the first-line treatment for erectile dysfunction in kidney transplant recipients.