Enterococcus faecium is Gram - positive cocci that is increasingly occuring as a cause of urinary infections in hospital area. Today, its virulence presents an increasing problem especially when it comes to vancomycin resistant strains. The aim of this study was to investigate the sensitivity of certain E. faecium isolates to antibiotics and characterize and present factors of virulence. Different methods were used to investigate the characteristics of pathogenic isolates: sensitivity to antibiotics, proteinase, lipase, gelatinase prodution, catalase, esculin hydrolysis, mobility, slime production and biofilm, haemolysis, aggregation and lysozyme resistance. It has been shown that there is resistance to ampicilin and norfloxacin in all 20 investigated isolates. Proteinases production is only shown in one tested isolate, while lipase has 75% of isolates. Negative results show galetinase, catalase, haemolysin (γ-haemolysis) and mobility in all isolates. Bile esculin are postive and in the slime production there are differences that consequently mean the formation of biofilms. A high percentage of aggregation >78% and lyzozyme resistance was demonstrated, with most of vancomycin resistant strains E. faecium. Conclusively, pathogenic isolates E. faecium demonstrated the presence of some of the most virulence factors in which the most important is the slime production and production of biofilm. Sesitivity to antibiotics is most significant in ampicillin and norfloxacin.