Sesamol (SM) is a dietary phytochemical present in the processed sesame oil. In this present study we have evaluated the antioxidant potential of SM and its role in the protection of radiation-induced DNA damage in γ-irradiated mice. The antioxidant properties of SM were evaluated by using different in vitro antioxidant assays. SM shows scavenging effect against hydroxyl (OH), superoxide anion (O(2)(-)), nitric oxide, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS(+)) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Our results demonstrate that SM exhibits strong antioxidant property in all the in vitro assays. When mice were exposed to 7 Gy γ-radiations there was an increase in % tail DNA, tail length, tail moment and Olive tail moment in blood lymphocytes. SM (100mg/kg b.wt) pretreatment significantly decreased the % tail DNA, tail length, tail moment and Olive tail moment in irradiated mice lymphocytes. These results suggest that SM protects γ-radiation-induced DNA damage in mice lymphocytes, which may be attributed to its antioxidant property.