Introduction: Natural products can be used as radioprotector agents because of containing phenolic compounds and several flavonoids with antioxidant properties. When the normal cells are exposed to ionizing radiation, they generate free radicals and reactive oxygen species that can cause damage in DNA, which leads to cellular dysfunction or even cell death. However, it is necessary to identify new radioprotective agents to protect normal cells. Ferulago angulata (F.angulata), a medicinal plant, can be used as a new radioprotective agent. Purpose: The antioxidant activity of F.angulata was assayed using FRAP and DPPH methods. Then, the human blood samples were incubated with F.angulata at different concentrations (25, 50, 100 and 200 μM) and subsequently exposed to IR at a dose of 2Gy. The radioprotective effectof F.angulata on the exposed cells was assessed by micronucleus (MN) method. Also, biomarkers of oxidative stress in the exposed cells were evaluated by malondialdehyde (MDA) and superoxide dismutase (SOD) methods. Methods: The antioxidant activity of F.angulata was assayed using FRAP and DPPH methods. Then, the human blood samples were incubated with F.angulata at different concentrations (25, 50, 100 and 200 μM) and subsequently exposed to IR at a dose of 2Gy. The radioprotective effectof F.angulata on the exposed cells was assessed by micronucleus (MN) method. Also, biomarkers of oxidative stress in the exposed cells were evaluated by malondialdehyde (MDA) and superoxide dismutase (SOD) methods. Results: Our findings showed that F. angulata reduced the frequency of MN induced by IR in exposed cells. At 200μM concentration of F. angulata, maximum reduction in the frequency of MN (63.11%) was observed that demonstrated a high degree of radioprotection. Afterward, pretreatment at 200μM concentration of F.angulata inhibited oxidative stress in irradiated lymphocytes, leading to a reduction in MN frequency and MDA levels while SOD activity was enhanced in the exposed cells. Conclusion: F. angulata as a natural radioprotective agent can protect normal cells against reactive oxygen species and genetic damage induced by IR.