Abstract: The author report one case of primary pulmonary diffuse large B-cell lymphoma of ¹⁸F-FDG PET/CT imaging. The characteristics of the disease were analysed according to clinical symptoms, laboratory examinations and ¹⁸F-FDG PET/CT imaging, meanwhile, the main points of differential diagnosis of primary pulmonary diffuse large B-cell lymphoma were reviewed in the literature. The results of imaging findings of ¹⁸F-FDG PET/CT in this case showed a large soft tissue mass with smooth edge and multiple spotty calcifications inside, ¹⁸F-FDG PET/CT imaging showed obvious ¹⁸F-FDG hypermetabolism in the mass with a SUV_max of 26.2. ¹⁸F-FDG PET/CT imaging could provide reference for diagnosis of primary pulmonary diffuse large B-cell lymphoma.