A 65-year-old laundryman who suffered from cough, fever, and dyspnea was admitted to our hospital. Laboratory finding disclosed leukocytosis of peripheral blood, elevated CRP, and hypoxemia. Chest X-ray films showed diffuse interstitial nodular shadows in both lungs. The patient was given a diagnosis of pneumonia and treated with oxygen inhalation, antibiotics, and steroids. The abnormal findings disappeared rapidly, and the patient was discharged after 11 days. However, he was readmitted 3 days later with the same chest X-ray film findings as observed before. Examination of bronchoalveolar lavage fluid disclosed an increased neutrophil count. Transbronchial lung biopsy specimens revealed alveolar collapse, which was considered to have contributed to hypoxemia and ventilation perfusion mismatch. However, no signs of infiltration of inflammatory cells into alveolar walls, or of acute-phase interstitial edema, were observed. Environmental studies supported a strong relationship between the patient's symptoms and clothes waterproofing agent. From these findings, we reasoned that the inhalation of aerosol waterproofing agent containing fluoroplastics can induce respiratory failure.