The results revealed that copper nanoparticles have shown high antibacterial activities, against clinical methicillin-resistant S. aureus strains, even higher than the activity of AgNPs (Tables 1 and 3) and reference antibacterial drug – ciprofloxacin and fluconazol . The nanoparticles of copper and silver reduced with hydrazine monohydrate showed also a high activity against clinical isolated strains, included highly multiresistant strains such as S. epidermidis and S. aureus. MIC values for standard and clinical Staphylococcus