Oxidative stress plays a central role in the pathogenesis of neurodegenerative, cardiovascular, and inflammatory disorders, as well as cancer. In this sense, the discovery of novel antioxidant agents has a critical priority in medicinal chemistry. Organoselenium derivatives stand out in this context for their ability to modulate redox processes, frequently mimicking the activity of glutathione peroxidase (GPx) .At the same time, the tetrazole nucleus functions as a bioisosteric moiety, widely employed in clinically approved drugs due to its favorable pharmacokinetic and pharmacodynamic properties. The strategic combination of these two pharmacophoric elements results in selenotetrazoles, molecules with promising biological potential and new perspectives for therapeutic development . The compounds were obtained via [3+2] cycloaddition between SeCN-containing precursors and sodium azide. In this work, the antioxidant activity of the newly synthesized selenotetrazoles was evaluated through radical scavenging assays (ABTS•+ and DPPH•) to investigate their redox-modulating potential. In the ABTS•+ assay, which measures the ability of molecules to neutralize radicals in aqueous medium, ethyl 3-(1H-tetrazol-5-yl)selanyl benzoate and ethyl 4-(1H-tetrazol-5-yl)selanyl benzoate at 200 µM showed significant antioxidant activity, comparable to ascorbic acid (positive control, 25 µM). Conversely, in the DPPH• assay, which evaluates electron transfer in apolar medium, the compounds showed no significant activity. This selectivity suggests that their antioxidant effect is not based on electron transfer in nonpolar systems, but rather occurs in aqueous environments, consistent with a GPx-like mechanism . In conclusion, the synthesized selenotetrazoles present selective antioxidant activity, redox stability and multitarget potential, consolidating them as promising scaffolds for the development of antioxidant, anti-inflammatory, neuroprotective and/or anticancer agents.