BACKGROUND Physical activity undertaken by stroke survivors is generally low. This trial investigated the feasibility of delivering a high-intensity treadmill and self-management program to people with stroke undergoing inpatient rehabilitation and determine whether physical activity, walking ability and cardiorespiratory fitness could be increased. METHODS A phase I, single-group, pre-post intervention study was conducted with stroke survivors undergoing inpatient rehabilitation who could walk. Participants undertook a high-intensity treadmill and self-management program for up to 30 min, three times a week for 8 weeks under the supervision of their usual physiotherapist. Feasibility was determined by examining compliance, satisfaction and adverse events. Clinical outcomes were amount of physical activity, walking ability, and cardiorespiratory fitness collected pre-training (week 0), post-training (week 8), and at follow-up (week 26). RESULTS Forty stroke survivors participated, completing 10 (SD 6) sessions, 94% at the specified training intensity, with high satisfaction and no adverse events related to the intervention. At week 8, participants completed 2749 steps/day (95% CI 933 to 4564) more physical activity than at week 0. Walking distance increased by 110 m (95% CI 23 to 196), walking speed by 0.24 m/s (95% CI 0.05 to 0.42), and VO2 peak by 0.29 ml/kg/min (95% CI 0.03 to 0.56). At week 26, increases in physical activity, walking distance and speed, and cardiorespiratory fitness were maintained. CONCLUSIONS A high-intensity treadmill training program embedded within a self-management approach during inpatient rehabilitation appears feasible and potentially may offer sustained improvements in physical activity, walking ability, fitness, and quality of life. A randomised trial is warranted. BACKGROUND This feasibility study was registered with the Australian New Zealand Clinical Trials Registry ( ACTRN12613000764730 ).