A 49-year-old woman was admitted with cough, general fatigue, and dyspnea on effort. Her hobby was the Japanese traditional handicraft of lacquer-carving. She sometimes used smut spores of Ustilago esculenta, pronounced as "Makomozumi"on lacquer ware. The chest radiographs showed diffuse ground-glass opacities and small centrilobular nodules. Bronchoalveolar lavage yielded a marked number of lymphocytes as well as total cell counts and a low CD4 +/CD8 + ratio. The transbronchial lung biopsy specimen revealed lymphocytic alveolitis and non-necrotizing epithelioid cell granulomas. The results of provocation test by Makomozumi were positive. Serum tests of the specific antibody against extracted soluble antigens of smut spores were positive. The peripheral lymphocyte proliferation test, performed with Mokomozumi antigens was also positive. The final diagnosis was hypersensitivity pneumonitis induced by smut spores of fungus Ustilago esculenta.