Tigecycline, a member of a new class of antimicrobials (glycylcyclines), was shown to have expanded broad spectrum activity against most commonly encountered species responsible for community and hospital acquired infections, including Gram-positive and Gram-negative multidrug resistant bacterial strains.The aim of the study was to evaluate the activity of tigecycline against resistant bacterial strains commonly associated with nosocomial infections, including skin structure, subcutaneous layer and intra-abdominal infections.Material and methods. Ten general hospitals from different regions of Poland participated in the study. Antimicrobial susceptibility tests were carried for 539 isolates of different genus/species of bacterial strains isolated from patients hospitalized in hospitals throughout Poland. Minimal inhibitory concentrations (MICs) of tigecycline were determined using the broth dilution method.Results. Ten strains of 50 S. aureus isolates, i.e. 20%, were methicillin-resistant (MRSA). The lowest MIC90 values observed for tigecycline were (0.25 μg/ml); they were similar to the MIC50 for MSSA and MRSA.S. pneumoniae varied with respect to their susceptibility to penicillin. Twenty two percent of isolates (n=11) had decreased susceptibility to penicillin. However, all 50 strains of this species were susceptible to levofloxacin, vancomycin and linezolid. Tigecycline exhibited high activity against S. pneumoniae strains. Tigecycline MIC90 values for this group of strains were lower than MIC90 of the remaining antibiotics. One hundred percent of collected S. agalactiae strains were susceptible to all investigated antibiotics.Conclusion. The presented data indicate that tigecycline exhibits excellent inhibitory activity against nosocomial and community pathogens regardless of resistance patterns.