[en] Testicular lymphoma only constitutes 1 to 7% of all testicular tumors, but the prognosis is worse because the primary testicular lymphoma is more lethal than testicular carcinomas. Only a few reports on the sonographic appearance of the primary testicular lymphoma have been published, but to our knowledge, there has been no report on this subject in this country. In this case report, the gray-scale and color doppler US findings of the primary testicular lymphoma in a 48-year-old man are described.