The morphological alterations caused by anabolic steroids (oestradiol and trenbolone acetate) on the Sertoli cells of testicles in animals for human consumption (lambs and calves) were studied. The morphopathological study of the treated lambs revealed delayed development of the seminiferous tubules, which was marked by signs of immaturity and even degeneration of Sertoli cells. The main morphopathological alterations affecting the Sertoli cells in calves occurred as hyperfunction symptoms marked by increased nuclei and smooth endoplasmic reticulum.