The present study investigated the radioprotective efficacy of lentil (Lens culinaris) sprouts against X-ray radiation-induced cellular damage. Lentil seeds were dark germinated at low temperature and the sprout extract was prepared in PBS. Free radical scavenging of extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and then the radioprotective potency of extract (0 to 1000 μg/mL) on the lymphocyte cells was determined by lactate dehydrogenases assay. Moreover, micronuclei assay was assessed using the cytokinesis-block technique. The irradiations were performed using 6 MV X-ray beam. The value of IC50 for DPPH assay was 250 μg/mL. The median lethal dose for radiation was determinate at 5.37 Gy. Pretreatment with lentil sprout extract at 1000 μg/mL reduced cytotoxicity at 6 Gy total concentration from 70% to 50%. The results of micronuclei assay indicated that cells were resistant to radiation at concentrations of 500–1000 μg/mL of exogenous lentil sprout extract. The value of median effective concentration for micronuclei assay was 500 μg/mL. The results indicated that lentil sprout extract showed actually somewhat radioprotective effect on lymphocyte cell. In addition, the obtained results suggest that extract of total lentil sprout have more antioxidant activity than radicle part.