A 54-year-old man was admitted to our hospital because of a nonproductive cough and back pain.Chest computed tomography (CT) showed an anterior mediastinal mass, multiple patchy lesions in both lung fields and left-sided pleural effusion. CT-guided biopsy specimens from the anterior mediastinal mass and pleural effusion samples were shown to be T-cell lymphoblastic lymphoma. Treatment with JALSG-ALL202 protocol resulted in diminishing all lesions remarkably. This is a rare case of T-cell lymphoblastic lymphoma with pulmonary infiltration.