A case of pulmonary lymphangiomyomatosis is reported. A 37-year-old woman was admitted with hemosputum and dyspnea on exertion. Chest roentgenogram revealed diffuse reticulonodular shadows and arterial hypoxemia was present. Pulmonary function tests showed severe restrictive & obstructive impairment, and pulmonary perfusion scintigraphy with 99mTc-MAA showed non-segmental disproportion. The histological diagnosis of pulmonary lymphangiomyomatosis was made by transbronchial lung biopsy. She underwent bilateral oophorectomy under general anesthesia. However, the arterial hypoxemia advanced gradually, and medroxyprogesterone-acetate (MPA) was commenced (200 mg/day). Her condition remained stable after the description of MPA.