In a prospective and randomized study comprising 540 primary endometrial carcinoma patients the influence of adjuvant hormone therapy by Oxyprogesterone caproate (OPC) and by its combination with Tamoxifen on the corrected survival rates after surgical and combined (surgical and irradiation) therapy was investigated. As was shown OPC administered preoperatively and after surgical and combined therapy from 6 up to 36 months increased the corrected survival rates as compared with that in patients who did not receive hormone treatment. Combination of OPC and Tamoxifen administered additionally to surgical and combined therapy increase the corrected survival rate at the 5th year by 19%. One can conclude that adjuvant hormone therapy in endometrial carcinoma patients who have unfavourable prognosis of the disease must be administered for not less than 3 years in order to obtain prolongation of remission of the disease.