This study was carried out on one hundred and twenty 14-day old Fayomi chicks in 6 groups(20 each)to detect efficacy of L.acidophilus  (as a natural immunopotentiator), Diclazuril (anti-coccidial drug) or both against E. tenella infection. Five groups were experimentally infected, at the age of 14-days, with E. tenella in a dose of 2 x 10⁴ oocysts/bird;amongthoseone group was given Diclazuril in a curative dose, another group was given the same drug in a prophylactic dose, a third group was given L. acidophilus, a fourth group was given both L. acidophilus and Diclazuril in prophylactic doses. The other two groups were kept as control infected non-medicated and control negative (non-infected, non-medicated). Number of shedding oocycts in drooping, changes in body weight gain, lesion scores of the necropsied birds and histopathological findings were used to evaluate the efficacy of both therapeutics. Comparing the obtained results showed that:  the best values were seen in the group given both L. acidophilus and Diclazuril followed by those groups given L. acidophilus only then the group given Diclazuril alone. The medicated groups were given better results than non-treated infected one. This revealed a distinct anti-coccidial effect of L. acidophilus and this provides a further insight to the antagonistic property of L. acidophilus and other natural microflora against infection with intestinal protozoa.