Design of compounds that can protect efficiently against gamma-rays irradiation is a great challenge. An ionizing event can cause variety of DNA damage scenarios leading to mutagenesis, cell death. 2-(1-Naphthylmethyl)-2-imidazoline (naphazoline, NP) is a drug belonging to the vasoregulator class, which was shown to be a very interesting compound in radioprotection. In order to highlight the NP radioprotective activity, a comparison of its ability to protect DNA against either gamma-irradiation or radicals generated by Fenton's reaction was made. Results show that NP inhibits efficiently the generation of DNA single-strand breaks and that NP is a potent radioprotector and also an hydroxyl radical scavenger.