A 79-year-old woman was admitted to hospital due to a four-month history of a cough and dyspnea on exertion. Chest CT scans revealed ground glass opacity with thickened interlobular septa in both lungs. Bronchoalveolar lavage fluid (BALF) had milky appearance and revealed large acellular eosinophilic amorphous bodies positively stained with periodic acid-Schiff (PAS). Autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF) were present in sera and BALF from the patient. Ambroxol was started in a daily dose of 45 mg orally. Her oxygen saturation improved and abnormal shadows in CT scan disappeared 6 months after beginning the therapy.