Twenty-four cases of extranodal non-Hodgkin's lymphoma presenting in the testicle are reviewed. All cases are diffuse lymphoma by the Rappaport classification. Cases clinically stages as I/II, (18/24) show a prolonged survival compared with those clinically staged as III/IV (6 of 24). Progressive involvement of either the lymphoid tissue in Waldeyer's ring or adjacent structures in the nasopharynx or oropharynx was noted in 22% (4 of 18) of Stage I/II cases. In 2 of the 24 (8%), there was asynchronous involvement of the opposite testicle. In patients with Stage I/II disease radiation therapy to the pelvic and paraaortic lymph nodes following inguinal orchidectomy is recommended. Systemic chemotherapy is recommended to follow radiation therapy unless bulky abdominal disease is present in which case it should precede radiation therapy. Prophylactic radiation of the opposite uninvolved testis is not recommended.