A 54-year-old man, a taxi driver who had consumed 30 pack-years of cigarettes but had not smoked for 3 years, had received a diagnosis of PAP 5 years before and had received whole-lung lavages several times thereafter. Dry cough and shortness of breath, however, recurred, and he was admitted to the hospital again in late September 2000. On examination, he was cyanotic with diffuse coarse crackles over both lungs. A chest radiograph showed diffuse alveolar infiltrates over both lungs. The Pao2 at the time of hospital admission was 49.1 mm Hg, and the Paco2 was 33.2 mm Hg while breathing room air. The results of a pulmonary function test showed a TLC of 62.2% and a Dlco of 42.8% predicted. The patient then underwent five FOB lavages on the third, fifth, ninth, 11th, and 15th day of hospital admission, respectively, for the right lower lobe, the left lower lobe, the right lower lobe, the left lower lobe, and the right lower lobe. The average volume of instilled saline solution was 1,920 mL, and that of the returning fluid was 500 mL. The patient’s Pao2 while breathing room air increased to 80.3 mm Hg 2 days after undergoing the final lavage. Polycythemia and LDH level declined. However, cough and dyspnea on exertion persisted, and radiographic opacities and the results of pulmonary function tests did not improve. He then received four cycles of whole-lung lavage (two for each lung). Symptoms improved, and radiographic infiltrates partially cleared after four whole-lung lavages (follow-up time, 6 months).