Flutamide, in therapeutic dose, has got many histological effects on the testis. In addition Flutamide reduces the gain in body weight in the growing animals, as well as it decreases the weight of the testis and increases the incidence of undescended testis. On the other hand Cimetidine has mild histological effect on the testis and low incidence of undescended testis. The effects of antiandrogens depend upon the antiandrogenic action and the time-specific-androgen receptors optimal sensitivity which involves the 16th and 17th gestational days. It is recommended that a further study to allocate the phase of androgen receptors activity and sensitivity in man corresponding to that observed in the experimental animals. Also to evaluate the effects of Flutamide and Cimetidine on the function of the male reproductive system especially fertility.