Chlorpyrifos (CF) an organophosphate insecticide broadly used for pest control and sterilization in agriculture applications. It has also established that CF toxicity linked to the increase of oxidative stress with accumulation of the lipid peroxides. CF poisoning causes the heart tissue to produce high quantity of free radicals, become sensitive to oxidative stress, and damage. Studies indicated that soy contains plenty of isoflavones, mainly genistein (GS), which have antioxidant properties. Current study designed to examine whether GS, daidzein (DZ), or their combination had any protection against CF induced cardiac toxicity in rats. Thirty adult female rats divided into five groups. Group 1 received corn oil. Group 2 received CF 6.7 mg/kg. Group 3 received 6.7 mg/kg CF + 21.7 mg/kg GS. Group 4 received 6.7mg/kg CF + 17.4mg/kg DZ. Group 5 received 6.7mg/kg CF + 21.7 mg/kg GS + 17.4 mg/kg DZ daily oral doses for six weeks. At the end, rats sacrificed and their blood samples and heart tissues collected for biochemical and histopathology analysis. Conclusion: administration of GS or DZ provides a protective effect against oxidative stress induced by CF. However, administration of GS and DZ together synergise oxidative stress induced by CF.