A 51-year-old man with Behçet's disease complained of fever, dry cough and dyspnea during exertion. Chest CT showed ground glass opacities with interstitial septal thickening in both lungs. Bronchoalveolar lavage (BAL) revealed amorphous and lipoproteinaceous material that was periodic acid-Schiff (PAS) stain positive. Transbronchial biopsy specimen demonstrated PAS positive alveolar eosinophilic material consistent with pulmonary alveolar proteinosis. Serum anti-granulocyte-macrophage colony stimulating factor (GM-CSF) antibody was negative. Recent studies have reported anti-GMCSF not present in the the serum of patients with secondary pulmonary alveolar proteinosis (PAP) but they have not reported so in patients with idiopathic PAP. We report a case of alveolar proteinosis in the setting of Behçet's disease with spontaneous remission.