In a review literary data and results of own investigations of colloidal nanosilver bases are summarized. A wide range of antimicrobial action of silver, the lack of resistance to it, effective against most pathogenic microorganisms, low toxicity, lack of data in the literature about the allergic properties , as well as good tolerability of patients - have contributed to increased interest in silver, in many countries around the world. Colloidal Silver is the safest and most potent natural antiseptic for the human body, that overwhelm over 700 species of pathogens, including staphylococcus, streptococcus, bacteria dysentery, typhoid, etc. It is proved that the water contaminated by high concentrations of bacteria became sterile after one or two hours from the introduction of the silver in amount up to 1 mg/l and maintained for many days. The drug is actively involved into reducing life and termination of pathogen bacteria, viruses, fungi and parasites, stimulate the protective mechanisms of the human body. In this case, it does not affect the benefic microorganisms. Silver by intravenous administration is successfully used for the treatment of septic arthritis, rheumatism, rheumatic endocarditis, rheumatoid arthritis, asthma, influenza, acute respiratory infections, bronchitis, pneumonia, purulent septic diseases, brucellosis, inside - in the treatment of gastritis, gastro-duodenal ulcers, externally - in the treatment of sexually transmitted diseases, septic wounds and burns. The results obtained in different studies on the effect of silver nanoparticles on the organisms are rather contradictory, but to forget about the relevance of this issue is not worth it.