Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) complicated with angioimmunoblastic T-cell lymphoma (AITL) is extremely rare and typically shows an aggressive clinical course and unsatisfactory prognosis. Here, we describe the case of a 77-year-old man who was referred to the hospital because of repeated fever, night sweats, and weight loss. He was finally diagnosed with a discordant lymphoma consisting of AITL and DLBCL, with significantly different maximum standardized uptake values on positron emission tomography/computed tomography. Based on his complex illness and poor performance status, the patient received six cycles of lenalidomide combined with R-miniCHOP regimen and achieved complete remission with tolerable and controlled toxicity. He subsequently received lenalidomide maintenance therapy and achieved sustained remission. We consider the possible causes of this discordance involved AITL and EBV-positive DLBCL, and the possible mechanism of lenalidomide action in both T-cell and B-cell non-Hodgkin lymphomas. Lenalidomide-combination therapy may be a preferable choice in patients with an EBV-associated discordant lymphoma.