Orchiectomy with adjuvant radiotherapy of retroperitoneal paraaortic and ipsilateral iliac nodes is the standard treatment for localized testicular seminoma (I, IIA, IIB). Post therapeutic follow-up allows to detect local relapse and radio-induced second cancer. Nevertheless, evaluation of risk of second malignancy still remains difficult. We report 2 cases of rectal cancer after radiotherapy for testicular seminoma.