The health benefits of regular aerobic exercise are well established, although there is limited high-quality evidence regarding its impact on erectile function. To determine the effect of aerobic exercise on erectile function in men and to identify factors that may influence this effect. This systematic review and meta-analysis included randomized controlled trials that evaluated the effects of aerobic exercise on erectile function via the Erectile Function domain of the International Index of Erectile Function (IIEF-EF). The mean difference in IIEF-EF scores between the aerobic exercise and nonexercising control groups was estimated by a random-effects meta-analysis. Meta-regression was used to evaluate the association of moderator variables on meta-analysis results. The IIEF-EF score is reported on a 6-30 scale, with higher values indicating better erectile function. Among 11 randomized controlled trials included in the analysis, aerobic exercise resulted in statistically significant improvements in IIEF-EF scores as compared with controls, with a mean difference of 2.8 points (95% CI, 1.7-3.9; P < .001) and moderate heterogeneity among studies (I2 = 53%). The effect of aerobic exercise on erectile function was greater in men with lower baseline IIEF-EF scores, with improvements of 2.3, 3.3, and 4.9 points for mild, moderate, and severe erectile dysfunction, respectively (P = .02). The meta-analysis results were not influenced by publication bias or individual study effects. Health care providers should consider recommending regular aerobic exercise as a low-risk nonpharmacologic therapy for men experiencing erectile difficulties. The primary strength of this review was the generation of level 1 evidence on a topic of general interest regarding sexual health in men. However, the included studies evaluated diverse groups, which may complicate data interpretation for specific segments of the population. Regular aerobic exercise can improve the erectile function of men, particularly those with lower baseline IIEF-EF scores.