In patients with peripheral artery disease (PAD), we evaluated the effects of 12 months of walking exercise at a pace inducing ischemic leg symptoms (high intensity) on the attainment of meaningful improvement in patient-reported outcome measures (PROMs) and 6-minute walk, compared to walking exercise at a comfortable pace (low intensity) and a nonexercise control. Participants completed the 6-minute walk test (6MWT) to evaluate objective walking ability. PROMs included the Walking Impairment Questionnaire (WIQ) distance and speed scores (range 0 to 100, 100-best, minimal clinically important difference (MCID) = 15 and 11, respectively). 240 participants (61.7% Black, 48.3% female) participated. High intensity exercise increased 6MWT compared to control (+44.8 meters (95% CI:21.7,68.0) and compared to low-intensity exercise (+37.6 meters [95% CI:18.6,56.5]). Low intensity exercise had no significant benefit compared to control (+7.3 meters [95% CI:-16.3,30.9]). High intensity significantly increased attainment of the MCID for the 6MWT compared to low intensity (OR:2.43 [95% CI:1.35,4.38]) and compared to control (OR:5.22 [95% CI:2.32,11.76]). Compared to control, high intensity exercise significantly increased the odds of attaining an MCID for the WIQ distance score (OR:2.30 [95% CI:1.05,5.04]) and WIQ speed score (OR:2.94 [95% CI:1.27,6.83]). Compared to low intensity, high intensity did not significantly increase the odds of attaining an MCID for the WIQ distance (OR:0.93 [95% CI:0.53,1.66]) or the WIQ speed score (OR:1.31 [95% CI:0.71,2.43]). In conclusion, in people with PAD, high intensity walking exercise increased the odds of meaningful improvement in PROMs compared to control, but not compared to low-intensity exercise. Despite this, high intensity exercise improved 6MWT more than the low intensity exercise and nonexercise control groups (NCT02538900).