Abstract: Primary pulmonary lymphoma(PPL) is a disease associated with low incidence and multiple pathological types, as well as the diversity of its medical imaging characteristics, which is susceptible to clinical misdiagnosis. Although biopsy is the “gold standard” for the diagnosis of PPL, it may not be acceptable for some patients due to its invasive procedure. On the basis of the morphological changes of CT, PET/CT further revealed the metabolic, molecular and receptor distribution features, which significantly improved the diagnostic accuracy.With the emergence of new molecular probes, PET/CT provides a non-invasive and more advanced method for the diagnosis and evaluation of therapeutic efficacy of PPL.The authors review the application progress of PET/CT in the diagnosis and efficacy evaluation of primary pulmonary lymphoma.