Silver nanoparticles and sulfur have been proved to possess significant antibacterial properties. In an attempt to improve nanosilver antibacterial properties, we prepared silver sulfide nanoparticles with sulfur component from three different sources including, thioacetamide (F1), ammonium sulfide (F2) and hydrogen sulfide gas (F3). Silver sulfide nanoparticles have been evaluated by European standards (CEN TC 216) in order to find out whether they could be applied in industrial, domestic and institutional areas as a suitable disinfectant or not. Moreover, bactericidal activity of silver sulfide nanoparticles has been compared to silver nanoparticles. Silver sulfide nanoparticels made by hydrogen sulfide gas not only passed the standards, but also showed more bactericidal activity against silver nanoparticles.