A clinicopathologic study was made on 26 patients with testicular lymphoma. Because they all presented scrotal swelling as an initial manifestation, they were thought to be affected with primary testicular lymphoma. The age at admission ranged from 39 to 87 years, with a median of 63 years. Stage of disease was I E in 8 patients, II E in 7, and III E in 8. Two- and five-year survival rates were 38% and 26%, respectively. The most common histological type was the diffuse large cell type, especially immunoblastic type. Immunohistochemistry revealed that almost all cases were B cell derived tumors. In our study, an obvious correlation between the histological type and the prognosis for patients could not be observed. However, the initial stage of the disease appeared to affect the outcome in patients with testicular lymphoma.