The authors performed an analysis concerning occurrence of the most important phenotypes of resistance to antibiotics among microbes isolated from focal infections recognized in 5 clinics of the Institute of Rheumatology (in the period from 2004 to 2005). Their occurrence or the dynamics of the occurrence determine serious clinical and therapeutic problems and should be systematically controlled. During the period of this analysis generally positive phenomena were also observed, for example: • the comparatively low percentage of MRSA strains (7.2%), • the marginal presence of Streptococci (Streptococcus spp.) with the mechanism MLSB resistance on macrolides, lincosamides and streptogramin B and Enterococcus spp. Vancomycin resistant (VRE) – in both cases after 1 isolate, • the low percentage (4.1%) of intestinal strains from the family Enterobacteriaceae generating b-lactamase with the extended substratum spectra (ESBL). The disadvantageous and, what is more, alarming tendencies include: • comparatively frequent (18.5%) isolation among CNS resistant strains phenotypes possessing MLSB mechanism resistance on macrolides, lincosamides and streptogramins B, MR-CNS (meticilin resistant – 50%) and multiresistant strains (72.7%), • high percentages (about 37%) of Enterococci resistant to high concentrations of aminoglycosides (HLAR), • frequent occurrence of multiresistance and ESBL strains among Gram-negative (not fermenting) reaching 80% and elevated percentage (18.2%) of resistance to carbapenems (last resort antibiotics). Additionally, the authors performed a detailed analysis of the occurrence of resistance to each chemotherapeutics among chosen taxa of microbes to facilitate usage for clinicians especially in empirical therapy. In the discussion the authors introduce the most frequent clinical implications which can accompany the estimated phenotype of the resistance, not always adequate to determined in vitro antibiotics sensitivity. Attention is also given to certain mechanisms leading to the generation of some phenotypes of resistance.