ObjectiveTo highlight the characteristics of pulmonary MALT lymphoma with diffuse lung disease. MethodsThe clinical,radiological and pathological data of two patients with pulmonary MALT lymphoma were analyzed,and relevant literature was reviewed. ResultsOne patient was a 59-year-old male with cough for five years while antibiotic treatment was ineffective. The chest CT scan demonstrated diffuse lung disease,bilateral multiple consolidation and ground-glass opacities,small nodules and bronchiectasis. Thoracoscopy biopsy was performed and the pathology study confirmed the diagnosis of MALT lymphoma. Another case was a 50-year-old female,who suffered from fever,cough and dyspnea. The chest CT scan revealed bilateral multiple patchy consolidation,with air bronchogram. The eosinophils count in blood was high. Diagnosed initially as eosinophilic pneumonia,she was treated with corticosteroids. The clinical symptoms were improved,but the CT scan revealed no change. After the computed tomography guided percutaneous lung biopsy,pathological examination confirmed the diagnosis of MALT lymphoma. ConclusionMALT lymphoma with diffuse lung disease is rare and easy to be misdiagnosed. The positive rate of bronchoscopy is low and percutaneous lung biopsy or thoracoscopy biopsy is more useful for diagnosis.