Desquamative interstitial pneumonitis (DIP) is a subgroup of interstitial lung disease that has a distinctive histopathology, with macrophages filling the alveolar spaces and no significant fibrosis. DIP has a strong association with cigarette smoking, and a better prognosis and response to corticosteroid. We report a patient with introgenic Cushing's syndrome who presented with progressive dyspnea and a bilateral diffuse ground-glass pattern on the chest roentgenograph, and who was diagnosed with DIP after video-assisted thoracoscopic (VATS) lung biopsy. Her condition was uneventful after treatment with corticosteroid. The development of DIP in this case may be associated with cigarette smoking and the abrupt discontinuation of the corticosteroid.