Pulmonary rehabilitation is effective for improving exercise capacity in patients with interstitial lung disease (ILD), and most programs last about 8 weeks. A 43-year-old male patient with systemic sclerosis and oxygen saturation (SpO(2)) declining because of severe ILD was hospitalized for treatment of chronic skin ulcers. During admission, he completed a 27-week walking exercise program with SpO(2) monitoring. Consequently, continuous walking distance without severe hypoxia (SpO(2) > 90%) increased from 60 m to 300 m after the program, although his six-minute walking distance remained the same. This suggests that walking exercise for several months may reduce the risk of hypoxia in patients with ILD, even though exercise capacity does not improve.