ABSTRACT: The long-term exercise capacity of coronavirus disease 2019 (COVID-19) patients with acute respiratory distress syndrome (ARDS) is not clear. The 6-minute walking distance (6MWD) of four patients with COVID-19-associated ARDS was followed for 6 months after admission to the hospital. These four patients were admitted to the intensive care unit (ICU) of our hospital and received mechanical ventilation. Rehabilitation therapy (positioning, postural drainage, and passive range of motion exercises) was started after ICU admission. Mobilization therapy, including muscle power training, sitting on the edge of the bed, and endurance training, was performed after the end of sedation. The Medical Research Council sum scores and Barthel Indexes for the patients improved after ICU discharge and completely recovered 6 months after admission to the hospital. However, the 6MWD of the four patients remained shorter than those of healthy persons of the same age at 6 months after admission to the hospital. Furthermore, the minimum SpO2 during the 6-minute walking test remained below 96%. It is possible that patients who receive mechanical ventilation due to COVID-19-associated ARDS have decreased long-term exercise capacity, despite muscle power and activities of daily living recovering completely.