Indium has been used for the production of flat-panel displays, including liquid crystal displays. Until 2007, the demand for indium in Japan totaled 85% of global demand. Accordingly, eight cases of indium lung disease, including the first fatal case, were revealed in Japan as the first in the world. In 2010, two cases in the United States and one in China were reported. However, the clinical features of indium lung disease in Japan and the U.S. were substantially different. The Japanese cases were diagnosed as interstitial pneumonia with numerous cholesterol crystals, but the diagnosis in the U.S. was pulmonary alveolar proteinosis (PAP). It has been 4 years since our case, the sixth in Japan, was diagnosed, and the follow-up pulmonary function test showed restrictive change for the worse; nevertheless, the patient's activity has not been limited. Though we rechecked the patient for signs of PAP, the clinical features of PAP were not evident, and the pathological diagnosis was alveolitis. Also, the backgrounds of the Japanese and U.S. cases obviously differ in such points as exposure duration, serum indium level, and value of GM-CSF auto-antibody. At this time, the reasons for these discrepancies are unclear.