A general review of hormone receptors in gynaecology describes the receptors of the membrane for polypeptide hormones and the receptors for steroids. The hormone stays intact in the case of the membrane receptor and activates by contact a second intra-cellular messenger which then induces protein biosynthesis. The constant of dissociation and the number of binding-sites in the human corpus luteum are established for HCG-LH during the cycle, during pregnancy or at the menopause. The working out of these receptors for levels of polypeptides by radio bio-assay gives biological specificity and radio-immunological exactness. Steroid receptors consist of a cytosol receptor which is activated and transferred to the nucleus to induce protein synthesis. They are well recognised for oestradiol and for progesterone in the endometrium and in pathological breast tissue. Variations in the cytosol receptors and the nucleus receptors are known for different phases of the menstrual cycle. Indications for hormone treatment in cancers of the endometrium and of the breast in human pathological conditions can be improved rapidly by recognition of these receptors.