One hundred twenty-five cases of testicular tumor are reviewed. The prognostic significance of clinical features, certain laboratory test results, and histologic type are evaluated, and treatment results are presented. The most important prognostic clinical feature is the presence or absence of clinically evident metastases. The urinary gonadotropin levels are useful prognostically, but the intravenous pyelogram and lymphangiogram are statistically unreliable. The presence of tumor in retroperitoneal lymph nodes influenced survival only in the patients with embryonal carcinoma. Tumor type influenced survival more than any other pathologic factor. Vascular invasion, local extension, and Leydig cell hyperplasia did not correlate with tumor behavior in germinal neoplasms. Patients with clinical Stage IA or IB teratocarcinoma had an 85 per cent survival rate with a wide variety of treatment.