79 patients with germinal tumors of the testes were treated at the University of Maryland Radiation Therapy Clinic between January 1, 1957 and December 31, 1973. 32 of 33 patients with stage I seminoma had disease controlled for a minimum of three years for a 96.9% 3 year disease-free determinant survival. 4 of 4 patients with stage I carcinoma were treated, two after negative node dissection, and all survived. 15 of 21 patients with stage II seminoma survived for 3 year disease-free Berkson-Gage actuarial survival of 68.5%, 9 of 21 stage II carcinomas, 18 of whom had had positive node dis-sections, survived for a 3 year disease-free Berkson-Gage actuarial survival of 42.8%. Benefit of adjuvant irradiation of the mediastinum and supraclavicular regions is demonstrated for stage II seminomas where 7/8 patients receiving prophylaxis demonstrated a 100% 3 year disease-free Berkson-Gage actuarial survival as opposed to the 50.4% in the 7/13 patients surviving without adjuvant therapy. This benefit is reaffirmed, although more tenuously, by the 71.4% 3 year disease-free Berkson-Gage actuarial survival demonstrated by the 5 of 7 stage II carcinoma patients receiving adjuvant therapy as opposed to the 28.2% demonstrated by the 4 of 14 patients surviving who did not receive adjuvant therapy.