In this study, in vitro antioxidant, antimicrobial and DNA damage protection potentials of the aqueous extract of Asplenium ceterach was firstly evaluated in addition to its total phenolic and flavonoid contents. Antioxidant activity was determined by five complementary test systems named β- carotene/linoleic acid, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, reducing power, chelating effect and phosphomolibdenum methods. Except for chelating effect assay, the extract exhibited remarkable activity potential. Antimicrobial activity was determined by agar-well diffusion and minimum inhibitory concentration tests. In this case, Shigella dysenteriae and Staphylococcus aureus were found to be the most sensitive microorganisms. According to the electrophoretic pattern of pBR322 plasmid DNA after treatment with UV and H2O2, supercoiled DNA was successfully protected in the presence of 20 mg/ml or above concentrations of aqueous extract.Key words: Antioxidant activity, antimicrobial activity, DNA damage protection, Asplenium ceterach