Back ground This study was undertaken to evaluate the effect of gamma radiation (1.5 KGy & 3 KGy) on L.q scorpion venom. This was carried out by studying the toxicological, biochemical & immunological properties of the venom before and after exposure to gamma radiation.   Material and methods Animals, venom, antivenin, gamma radiation, ¹²⁵I.   Results Data revealed that the toxicity of irradiated venom (1.5 KGy & 3 KGy) decreased as compared to that of the native one. LD₅₀ of irradiated venom were 3.5 mg/kg & 7.5 mg/kg respectively while, that of the native venom was (0.39 mg/kg). Moreover, the distribution of ¹²⁵I-labeled L.q venom was studied in male Swiss mice tissue using chloramine-T method by being injected intravenously. At various time intervals, urine and blood were collected and the animals were sacrificed. Brain, lungs, heart, liver, kidneys, spleen, intestine, bone and muscle were isolated in order to determine the radioactivity content. The highest contents of ¹²⁵I-labeled L.q venom were found in the liver and kidney that were quickly excreted into the urinary tract. Trial to label irradiated (1.5 & 3 KGy) L.q venom was unsuccessful due to its decomposition.  For that reason the utilization of the labeled irradiated L.q venom is of no meaning. In immunodiffusion technique, both irradiated and native venoms exhibited prominent precipitin bands indicating high concentration of specific antibodies against polyvalent antivenin with venom. Furthermore, the effect of half the LD₅₀ of native or irradiated (1.5 KGy) L.q venom was studied on the activities of certain enzymes: ASAT, ALAT, LDH, CPK, CPK-MB, and the levels of total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and the oxidative stress biomarkers (plasma MDA & blood GSH). Biochemical measurements showed that scorpion venom envenomation caused significant (p < 0.05) elevation in serum ASAT, ALAT, LDH, CPK as well as CPK-MB activities, blood GSH level while, caused significant (p < 0.05) reduction in triglyceride, HDL-cholesterol. In contrast, the 1.5 KGy gamma irradiated L.q venom showed no alterations except in HDL-cholesterol that significantly decreased compared to that of the non-envenomated normal rats.   Conclusion These results indicated that 1.5 KGy gamma irradiation of venom offer an effective method for reducing the toxic effect of venom.