Soya isoflavones are compounds with phytoestrogenic characteristics, i.e. because of their structure, their effects are similar to those of animal estrogens. This is why they are used for medicinal purposes in aging women. The presented experiment with laying hens was conducted to demonstrate the possibility of transferring soya isoflavones from feed into egg yolk to produce isoflavone-enriched eggs. Laying hens were randomly assigned to a control and 3 experimental groups and fed a basal diet or the basal diet supplemented with different concentrations of isoflavones: 1000, 2000 or 3000 mg · kg^–1 feed. The transfer of isoflavones (daidzein and genistein) from the feed into the egg yolk of treated hens was found to be significant. At the end of the experiment, the content of the analysed isoflavones was from 396.0 to 412.4 μg.