Objective:To investigate the 18F-FDG PET/CT manifestations and diagnostic value in patients with pulmonary mucosa associated lymphoid tissue lymphoma. Methods:Clinical records and characteristic18F-FDG PET/CT findings in 3 patients with pulmonary mucosa associated lymphoid tissue lymphoma confirmed by pathology,were retrospectively analyzed. Results:The main chest CT manifestations of pulmonary mucosa associated lymphoid tissue lymphoma were single or multiple mass with blurred contours,consolidation with air bronchogram and localized alveolar opacity. Pleural tuberous thickening,pleural effusion and lymph node swelling were also seen. Three patients had high FDG uptake lesions. Conclusion:Pulmonary mucosa associated lymphoid tissue lymphoma is an unusual subtype of non-Hodgkin lymphoma. Imaging manifestations are mass with blurred contours or consolidation with air bronchogram and high FDG uptake. The final diagnosis should be made by histology and immunohistochemistry.