The aim of the study was to investigate the presence of α (Erα) and β (Erβ) oestrogen receptors in rabbit male’s claustrum, and thus to examine whether oestrogens may influence nerve cells’ functions of this structure. The material for the study was obtained from the brains of seven rabbits. To detect the presence of Erα and Erβ, specific monoclonal antibodies were used. The expression of Erα and Erβ was demonstrated in proper claustrum, as well as in the nucleus endopiriformis. For Erβ, the reaction occurred mainly in the cell nucleus, whereas Erα was localised predominantly in the neuron cytoplasm. For both Erα and Erβ, the nuclear and cytoplasmic localisation was observed in a small percentage of the examined cells. The obtained results may indicate oestrogen influence on the brain area and also suggest a further research on oestrogen-dependent pathways in males, which still remain greatly unexplored.