Aim: To investigate the effect of vitamin E on the radioprotection of spermatogenesis and chromatin condensation of spermatozoa during passage through the epididymis in mice exposed to irradiation. Methods: Adult outbred male ICR mice were orally administered natural vitamin E (VE, D-α-tocopheryl acetate) at 400 IU/kg for 7 days before exposure to 1 Gy of γ-irradiation. The animals were sacrificed at day 1, 7, 14, 21, 28, 35 and 70 post-irradiation (IR) and the percentage of testicular germ cells and epididymal sperm chromatin condensation was analyzed using flow cytometry. Results: Serum D-α-tocopheryl acetate levels were 47.4 ± 3.2 μg/dL in the treated group, yet it could not be detected in the control group. The testicular weight of irradiated mice pretreated with VE+IR was significantly (P<0.05) higher than that of those without VE treatment (IR) at day 14 and 21 post-irradiation. The percentage of primary spermatocytes (4C) in the VE+IR group was comparable to the controls but significantly (P< Aim: To investigate the effect of vitamin E on the radioprotection of spermatogenesis and chromatin condensation of spermatozoa during passage through the epididymis in mice exposed to irradiation. Methods: Adult outbred male ICR mice were orally administered natural vitamin E (VE, D-α- tocopheryl acetate at 400 IU / kg for 7 days before exposure to 1 Gy of γ-irradiation. The animals were sacrificed at day 1, 7, 14, 21, 28, 35 and 70 post-irradiation (IR) and the percentage of Testicular germ cells and epididymal sperm chromatin condensation were analyzed using flow cytometry. Results: Serum D-α-tocopheryl acetate levels were 47.4 ± 3.2 μg / dL in the treated group, yet it could not be detected in the control group. The testicular weight of the irradiated mice pretreated with VE + IR was significantly (P <0.05) higher than that of those without VE treatment (IR) at day 14 and 21 post-irradiation. The percentage of primary spermatocytes (4C) in the VE + IR group was comparable to the controls bu t significantly (P <