129 cases of malignant testis tumors (88 seminoma and 41 carcinomas) treated at Istituto del Radio "O. Alberti" from 1966 to 1979 were statistically reviewed. All patients had inguinal orchiectomy followed by irradiation to iliac and lumbar para-aortic lymph nodes, with an original technique, tangential pendular cobalt therapy, worked out at our Institute in 1966. Results are very good: there is calculated with actuarial method, a 92% of patients with seminoma alive at 5 years and 84% of patients with carcinoma. Earlier or later iatrogenic sequences did not happened. The worth and actuality of tangential pendular cobalt therapy to post-operative irradiation in patients with stage I or II malignant testis tumors is confirmed.