The aim of this was to elucidate the effects of deltamethrin dipping on acetylcholine activity in serum and some blood parameters of sheep. The study was conducted on forty adult sheep dipped in deltamethrin in concentration of 1:1000L of water. Venous blood samples were collected from each animal before and after dipped. There was significant inhibition in the acetylcholine esterase in all subjected animals after dipping. Mean values of hematological investigations showed a significant rise in the number of total leucocytes (leukocytosis) with significant decline in hemoglobin concentration and Red cell indices in all dipped animals after dipping in deltamethrin when compared with mean values obtained from the same animals before dipping. Conclusion of our results revealed that poisoning with deltamethrin affects blood parameters through the inhibition of acetylcholine esterase.