The purpose of this study was to evaluate the influence of a home-based walking program on erectile function and the relation between functional capacity and erectile dysfunction (ED) in patients with recent myocardial infarctions. Patients with acute myocardial infarctions deemed to be at low cardiovascular risk were randomized into 2 groups: (1) a home-based walking group (n = 41), instructed to participate in a progressive outdoor walking program, and (2) a control group (n = 45), receiving usual care. Functional capacity was determined by the 6-minute walk test and evaluation of sexual function by the International Index of Erectile Function questionnaire; the 2 tests were performed at hospital discharge and 30 days later. In the overall cohort, 84% of patients reported previous ED at hospital discharge. After 30 days, ED had increased by 9% in the control group in relation to baseline (p = 0.08). However, the home-based walking group had a significant decrease of 71% in reported ED (p <0.0001). The 6-minute walk distance was statistically significant higher in the home-based walking group compared with the control group (p = 0.01). There was a significant negative correlation between 6-minute walk distance and ED 30 days after hospital discharge (r = −0.71, p <0.01). In conclusion, an unsupervised home-based progressive walking program led to significant improvements in functional capacity in men at low cardiovascular risk after recent acute myocardial infarctions. In addition, this intervention demonstrated a link between functional capacity and exercise training and erectile function improvement.