Prevalence of Klebsiella pneumoniae among gramnegative pathogens of nosocomial infections in intensive care units of 33 hospitals of 22 towns in Russia was investigated. Antibiotic susceptibility and extended-spectrum beta-lactamase production were tested in 420 nosocomial K. pneumoniae isolates. Carbapenems (imipenem, meropenem and ertapenem) showed the highest activity. Extended-spectrum beta-lactamase production based on the phenotyping methods was revealed in 342 (81.4%) isolates. The maximum activity against the K. pneumoniae isolates producing extended-spectrum beta-lactamase was observed in imipenem and meropenem (no unsusceptible strains were isolated). 3.2% of the isolates was not susceptible to ertapenem. Differences in the activity of cefoperazone/sulbactam, amikacin, ciprofloxacin and levofloxacin against the extended-spectrum beta-lactamase producing isolates in various hospitals were recorded.