Primary non-Hodgkin's lymphoma of the testicle is rare. We analysed cases treated in French anticancer centres from 1969 to 1995. All cases were reviewed and classified according to the R.E.A.L. Classification. Eighty-four cases were included in this study. The median age was 67 years (17-85). Disease was classified as stages I in 42 cases, stages II in 19 and stages III-IV in 23. Diffuse large B-cell lymphoma was diagnosed in 75% of cases. Treatment included orchidectomy and radiotherapy and/or chemotherapy. A complete response was obtained in 72.6% of the patient population and in 100%, 68% and 33% of stage I, II and III-IV disease respectively. Recurrence occurred in 32 cases and the most frequent site was the central nervous system: six of these patients presented stage I disease. Median overall survival was 32 months for the entire population, 52 months for stage I, 32 months for stage II, and 12 months for stage III-IV cases (P < 0.0001). Among patients presenting stage I disease, no difference was found between those treated with combined surgery and chemotherapy or surgery followed or not followed by radiotherapy. This study confirms that non-Hodgkin's lymphoma of the testicle carries a poor prognosis. Systemic adjuvant chemotherapy should be discussed because of the high recurrence rate. Inclusion of these cases in large co-operative prospective studies is recommended.