From June 1977 through June 1987, 46 patients (36 evaluable) affected by stage I and II non-bulky testicular seminoma were treated with postoperative telecobaltotherapy (TCT). In stage I seminomas, radiotherapy was extended to the omolateral iliac and the para-aortic areas (total dose: 30 Gy over 4 weeks). In stage II seminomas, the subdiaphragmatic lymph nodes were irradiated with 40-45 Gy over 5-6 weeks; after an interval of one month the subdiaphragmatic lymph nodes were irradiated again with a total dose of 25 Gy over 3.5 weeks. Minimal follow-up lasted two years and maximum ten years (average: 5.5). Two (5.5%) recurrences occurred, but salvage radiotherapy and salvage chemotherapy respectively allowed a complete permanent remission. One patient died from a different neoplasia with no evidence of testicular involvement. The 5-year actuarial survival is 96.6 +/- 3.4. In 20% of the patients the side effects were nausea and/or vomiting, easily controlled. No late complications were observed.