The aim of the study was to compare the localisation of oestrogen receptors alpha and beta (ER alpha and ER beta) in the human and rat epididymides. In the human epididymis the immunoexpression for ER alpha was detected in the nuclei of the caput epithelial cells, while positive reaction for ER alpha was observed in the nuclei of the cauda epithelial cells. In the rat epididymis, immunoexpression for ER alpha showed nuclei of the caput and cauda epithelial cells. However, the reaction was stronger in cells of the caput epididymis. A positive reaction for ER beta was observed in the nuclei of smooth muscle cells of the epididymal duct and in the nuclei of interstitial tissue cells of the rat caput and cauda epididymis. We have demonstrated that localisation of ER alpha and ER beta is cell-, region- and species-dependent.