A full-term newborn infant had the onset of respiratory distress immediately after birth. She required supplemental oxygen from birth, and had pulmonary alveolar proteinosis (PAP) documented by open lung biopsies at 6 and 12 weeks of age. Light and electron microscopy showed dense, PAS-positive granular, homogeneous material within the alveolar spaces, diagnostic of PAP. No Pneumocystis carinii organisms were demonstrated on silver staining, and bacterial and viral cultures were negative. The infant died of progressive respiratory insufficiency at 1 yr of age. Pulmonary alveolar proteinosis should be considered a rare cause of chronic respiratory distress in the newborn infant.