Human T-cell lymphoma virus (HTLV)-associated adult T-cell leukemia lymphoma is a rare cancer in the United States, but there are several areas around the world where the virus is endemic. HTLV-associated adult T-cell leukemia lymphoma has been associated with leukemic arthropathy. We present a patient with HTLV-associated adult T-cell leukemia lymphoma with leukemic arthropathy. Although non-steroidal anti-inflammatory drugs and chemotherapy are often used for treatment, we describe the successful use of radiation therapy in the palliative relief of symptoms from leukemic arthropathy.