In Japan, most cases of malignant lymphoma arising in the thorax are pyothorax-associated lymphoma, which develops in patients who have undergone artificial pneumothorax, used in the past as surgical therapy for pulmonary tuberculosis. Pyothorax-associated lymphoma consist mostly of diffuse large B-cell lymphoma and have a strong association with EBV. Herein is reported the case of a diffuse large B-cell lymphoma arising in the left thoracic wall after left lung resection for squamous cell carcinoma and chest wall reconstruction with polyethylene terephthalate (PET) surgical mesh. The tumor was found 20 years after the operation and was confined to the chest wall adjacent to the PET mesh. The patient did not have a clinical history of pyothorax after surgery. The lymphoma cells were of the large cell type and were positive for CD20, EBV-encoded small RNA--in situ hybridization, LMP-1 and EBNA-2. The present case demonstrates that EBV-related B-cell lymphoma can occur after surgery other than artificial pneumothorax. In the present case, long-standing chronic inflammation induced by PET mesh may have been associated with the development of lymphoma.