Abstract: Objective To analyze the chest X-ray and CT findings of pulmonary alveolar proteinosis (PAP) in an effort to improve the accuracy of diagnosis. Methods The imaging findings by chest X-ray and CT of 6 proven PAP cases (by imaging examinations, autopsy and bronchoalveolar lavage) were retrospectively analyzed on the basis of literature review. Results Chest X-ray and CT presented diffuse small nodules in both lungs in the 6 cases, also showing scattered small or large patches of ground-glass opacity (GGO) along with consolidation in the lungs. CT also showed reticular shadows (creating typical crazy-paving appearance) and signs of bronchial air in the patches of GGO. Conclusions X-ray film can find the pulmonary lesions but is usually unable to establish a definite diagnosis. Chest CT is capable of revealing the extent, delineation and characteristic manifestations of PAP, which helps to derive a definite diagnosis in combination with a thorough review of the patients’ clinical history.