Ionizing radiations damage cells, tissues and organs among which the liver through a cascade of molecular events that are triggered by reactive oxygen species (ROS), lipid peroxidation and nitrogen species (NS). Aged Garlic Extract (AGE) has been demonstrated to possess free radical scavenging capacity and antioxidant activity. Therefore, the present study has been focused in analyzing the properties of AGE against the lipid peroxidation and oxidative damages of rat liver tissues induced by acute radiation. Eight groups, five healthy male rats each were used (20 irradiated and 20 Sham Irradiated), among which some were receiving via gavages distilled water, the others AGE at different doses (25 mg/kg and 50 mg/kg) and the rest vitamin E + Alpha Lipoïc Acid. Then, biochemical analyses, lipid peroxidation, total Protein and antioxidants assessment were made from blood samples and liver tissue homogenates. Exposure of rats to gamma radiation caused a significant increase in the level of Malondialdehyde, Nitrite, transaminase enzymes, alkaline phosphatase, and Bilirubin (Total Serum Bilirubin, Direct Bilirubin and Unconjugated Bilirubin) level while a significant decrease was recorded in serum total proteins, glutathione content, superoxide dismutase, catalase activities and total protein level. AGE treated rats revealed a significant improvement in all previous parameters. From these results, it can be concluded that AGE may have significant anti-radiation properties in rat's liver after radiation exposure.