Desquamative interstitial pneumonia occurred in three siblings. Cough, difficulty in breathing, cyanosis, and failure to gain weight appeared during the first month of life; progressive hypoxia followed, and the three infants died in respiratory failure before the age of 4 months despite intensive drug and supportive treatment. The radiographic and the histologic appearance of pulmonary changes were similar in all three infants. Chest radiographs yielded normal findings initially, with rapid progression to a ground glass appearance of both lungs. Histologic findings of lung biopsies showed lymphoplasmocytic infiltration and fibrous thickening of the alveolar walls, swelling of alveolar lining cells, and large clumps of macrophages with PAS-positive foamy cytoplasm in the alveolar spaces.