METHODS: The present study reported a patient with acute interstitial pneumonia (AIP), who was admitted to hospital for cough, fever and progressive dyspnea. Chest high-resolution computed tomography (HRCT) showed diffuse bilateral infiltrates in rapidly development, which were characterized by grid pattern, cord-like image and ground glass attenuation in subpleural area of bilateral lung. He has a histological proof of diffuse alveolar damage consistent with acute interstitial pneumonia, obtained by transbronchial lung biopsy (TBLB). Pulmonary function tests showed severe restrictive ventilatory dysfunction and moderate diffuse dysfunction. He was clinically diagnosed with AIP.