Abstract: Snake-bite is considered a neglected tropical disease that affects thousands of people worldwide. Administration of antivenom is the corner stone in the therapy of snake bite. The study aimed to improve the production of antivenom using calcium phosphate nanoparticles (CPN) as adjuvant and gamma irradiation to detoxify venom. This was carried out by studying the toxicological and immunological properties of the Naja haje venom before and after exposure to 2 KGy gamma radiation. Furthermore, the cardiotoxic and hepatotoxic biomarkers of the envenomed rats were examined to compare the effect of native and gamma irradiated venoms. Moreover, in order to achieve the goal of the present study the immune response of immunized rabbits was evaluated through determination of antibody titer using ELISA technique and comparing the neutralizing capacity for lethality and enzyme activities of the serum obtained from rabbits inoculated with Naja haje venom in its native and ? irradiated form in presence of CPN as adjuvant or complete Freund's adjuvant. Data revealed that the toxicity of ? irradiated Naja haje venom was reduced 6 times as compared to the native venom. There was no change in the antigenic reactivity between both native and ? irradiated Naja haje venoms. Furthermore, injection of ? irradiated Naja haje venom did not significantly change activities of serum LDH, CPK, CK-MB, ALT and AST as compared to the normal group.