Seven patients with stage I and II primary testicular lymphoma (PTL) have been treated since 1990 to the present at Kawasaki Medical School. All patients, whose median age was 56 yrs, had initially complained of swelling of the scrotal contents. The lesions were on the right in two patients, on the left in five, and no patient had bilateral lesions. The histological diagnosis was diffuse large B-cell type in all patients. Five patients were classified as Ann Arbor stage I, and two at stage II. After high-orchiectomy for resection of tumor, two patients received chemotherapy alone, with a combination of chemotherapy and irradiation of the contralateral testis in the remaining five. Complete remission was achieved in all seven patients, but relapse occurred later in one. As it is recognized that, even in localized stage or low risk group PTL patients, the relapse rate in the central nervous system (CNS) and contralateral testis is quite high, chemotherapy, prophylactic CNS treatment and radiation of the contralateral testis after tumor resection should be included in the management of PTL.