Hundred Cobb chicks of one day old were used in this study. The chicks were divided into 4 groups (n = 25 / group). Group 1 was used as a control group; groups 2, 3, and 4 were experimentally infected with Eimeria tenella (E. tenella) at the 14th day of age. G2 received no treatment; G3 and G4 were treated with diclazuril 1ml/4 L in drinking water and toltrazuril 7 mg/k.g B.wt for 2 successive days respectively at 5 days post infection. The obtained results revealed significant decreases in hemoglobin concentration, red blood cells counts and PCV% in the infected group compared with the control group. The levels of SOD were significantly decreased while MDA level was significantly increased and the levels of IL -2 and IL- 6 were increased in E. tenella infected group. Histopathological results revealed heavy infestation of the intestinal crypts with different developmental stages in Eimeria tenella infected group compared with control group. The treatment with diclazuril and toltrazuril improved the deterioration caused by E. tenella, particularly the diclazuril treated group.