A 74-year-old man who had been suffering from dry cough and shortness of breath for 4 months after regular use of the oral chondroitin and hyaluronic acid supplement was admitted to our hospital. Chest radiographs and computed tomograms revealed interstitial infiltrations and peribronchial opacities with bronchiectasis in the bilateral lung fields. Total cell counts, percentage of lymphocytes, and the CD4/CD8 ratio in the bronchoalveolar lavage fluid were 2.5×10⁵/ml, 55.2%, and 0.58, respectively. Pathological examination of lung tissues obtained by video-assisted thoracic surgery demonstrated nonspecific interstitial pneumonia and organized pneumonia with proliferations of eosinophils and type II pneumocyte cell hyperplasia. The symptoms and lung abnormalities associated with drug-induced pneumonia were improved immediately without systemic corticosteroid therapy after the oral supplements were suspected to be responsible and were subsequently withdrawn. To our knowledge, this is the first reported case of pneumonia induced by oral intake of chondroitin and hyaluronic acid supplement.