Genes located only on the Y chromosome are male specific and are thus not expressed in female cells, which results in gene dependent sex differences. One of the genes located on the Y chromosome and expressed only in male cells is Kdm5d. In our study, the hypothalamus was compared between female and male SF-1 KO, intact WT and gonadectomised WT mice to investigate the genetically and hormonally dependent differences between the expression of the protein encoded by the Kdm5d gene. Standard immunohistochemical staining on floating brain sections was used to visualize the Kdm5d protein and was further analysed under the microscope. Immunoexpression of Kdm5d protein was observed only in WT intact males, but was not detected in any other groups. This observation suggests that the expression of the Kdm5d protein is both genetically and hormonally conditioned. Further experiments with testosterone supplementation should be carried out to confirm our findings.