The public discussion and the discussion among gynaecologists about the possible increased risk to develop carcinoma of the endometrium following post menopausal treatment with estrogens has lead to insecurity and restricted attitudes in the prescriptions of estrogens. In a statistic comparison of matched pairs of 130 cases of carcinoma of the endometrium with an equal number of selected control cases the following findings were elucidated: 1. Any estrogen preparations do not increase the relative risk for the development of carcinoma of the endometrium. 2. Differentiation into conjugated estrogens, estriol, oral contraceptives and various other estrogen compounds showed a similar trend. 3. Estrogen-androgen compounds and estrodiol compounds did not increase the relative risk for endometrial carcinoma. 4. The relative risk does not increase by prolonged ingestion of estrogen preparations in general and not for conjugated estrogens especially. 5. In the presence of other risk factors such as nulligravity, hypertension, obesity the relative risk for the development of carcinoma of the endometrium is significantly decreased when estrogens were taken, especially when the coincidental risk factor to estrogen ingestion was obesity. The above results suggest that the restraint in the prescription of estrogen for fear of endometrial carcinoma is not justified.