The clinical features and results of treatment in 12 cases of [human] malignant lymphoma in 280 consecutive testicular tumor cases are reported. The tendency of these neoplasms for bilateral involvement and the association with skin and upper respiratory tract lesions, reported in the literature, were confirmed. Long survival of a few cases after orchiectomy or regional treatment only (2 in the present series) suggests the existence of malignant lymphoma of the testis as a primary condition, although in most cases a lymphomatous involvement of the testis must be considered as a local manifestation of disseminated lymphoma.