Endometrial carcinoma, now the most frequent female genital tract malignancy in Denmark, is generally accepted as an endocrine-related neoplasm. Like normal endometrium, many endometrial carcinomas contain estrogen receptors as well as progesterone receptors. The receptor content appears to correlate with several histopathological features, in particular with tumour differentiation. Well-differentiated lesions are more frequently estrogen and progesterone receptor "positive" than poorly differentiated lesions. Several studies suggest that a high content of estrogen/progesterone receptors in primary endometrial carcinomas, regardless of other prognostic factors, affects the prognosis favourably. Furthermore, receptor status seems to correlate with response of the tumour to progestin therapy. It may be of particular importance, that nearly half of poorly differentiated endometrial carcinomas contain estrogen/progesterone receptors and thus might benefit from progestin therapy. Immunohistochemical receptor analysis directly on cryostat or formalin-fixed tissue sections increases the possibility to explore the histological and biological features, which are determinative for the receptor profile of endometrial carcinomas.