Between 1971 and 1983, 26 Patients with testicular pure seminoma treated at the Yonsei Cancer Center with radiotherapy are analyzed. The stage distribution was: stage I 46%(12/26), stage B 42%(11/26), and stage III 12% (3/26). Tumor histological subtypes were typical seminoma in 8 patients, anaplastic seminoma in 4 patients, and unknown subtypes in 14 patients. Three-year actuarial disease free survival rate was: overall 76%, stage I 91%', stage II 80%, stage III 0%, Treatment failure were analyzed to determine their apparent causes and the implication of such failures to the future management of the testicular pure seminoma.