Zinc oxide nanoparticles (ZnO-NPs) have attracted considerable interest owing to their physicochemical properties and vigorous biological activity. In this research, ZnO-NPs were synthesized using aqueous extract of Sargassum vulgare (SVE) as a reducing and capping agent. Morphological and physical features were analyzed through Uv–visible, SEM, TEM, XRD, EDX, DLS and zeta potential studies. (342 characters)