A 71-year-old man with malaise, anorexia, and weight loss was referred to our hospital from a clinic. Abdominal computed tomography(CT)revealed bilateral adrenal masses. An ultrasound-guided percutaneous needle biopsy of the adrenal grand indicated diffuse large B-cell lymphoma. A rapid adrenocorticotropic hormone(ACTH)test revealed primary adrenal failure. Rituximab-cyclophosphamide/doxorubicin/vincristine/prednisolone(common name, R-CHOP)therapy accompanied by intrathecal treatment was initiated along with steroid replacement therapy. After the fourth courses, a CT scan showed a reduction of the adrenal masses, and there was no[18F]-fluorodeoxyglucose(FDG)uptake in the adrenal masses. The patient has remained in metabolic complete remission. Subsequently, both adrenal lymphomas were irradiated. The patient has been disease-free for 6 months after the diagnosis of primary adrenal lymphoma. The combined modality of chemoradiation therapy plus intrathecal treatment could be effective for primary adrenal lymphoma with a poor prognosis.