The results of high energy radiotherapy in patients who had been orchiectomized for testicular seminoma are reported. The treatment includes irradiation of cruro-inguinal lymph gland, lumbo-aortic and left subclavian stations and produced extremely positive results (no recurrences or secondary metastasis) in almost all cases treated. The cases were controlled serially over time with an average follow-up of 5 years. The treatment did not give rise to side-effects or changes in blood clotting.