The general aim of this paper was to characterize some changes induced by androgen receptors blockage in the epithelial cells of the mouse epididymis. The antiandrogen flutamide was injected (10 mg/Kg b.w.) to adult male mice which were sacrificed 24h. and 72h. after. Controls injected with the vehicle (corn oil) were sacrificed at the same intervals. Cryosections were made of the epididymides and examined by the TUNEL method for quantification of apoptosis and also using immunocytochemistry to visualize the expression of the stress protein HSP70. The highest indexes of apoptosis were observed in the caput epididymis after 72 h. and were of 7.40 cells/1000 in contrast to controls (0.21 cells/1000). HSP70 appeared particularly increased in the caput and cauda epididymis after 72 h. treatment. Results indicated that the blockage of androgen receptors induces apoptosis and a HSP70 expression in the principal epithelial cells of the mouse epididymis, and that these changes occur in a region-specific fashion.