AgEDTA complexonate was synthesized, the manner of coordination of the Argentum (I) ion to the functional groups of complexone was determined. It was found that the solid complex precipitates from the solution in the form of a fine powder. It is shown that the size and shape of nanoparticles of Argentum complexonate depend on the solvent-precipitator. A stable dispersed system based on the synthesized complexonate was obtained. The shape and position of the surface plasmon resonance bands confirm the presence of spherical nanoparticles with a size of 15–30 nm in both dispersed systems. Investigations of the biological activity of the powder of AgEDTA has shown that it has a high bactericidal effect against gram-positive bacteria.