Klebsiella pneumoniae is the most common causes of pneumonia, urinary tract and bloodstream infections in patients in intensive care unit (ICU). In this study, twenty-two K. pneumoniae cultures were isolated from patients with respiratory tract infections in the same intensive care unit during 2010. All isolates were characterized by XbaI-pulsed-field gel electrophoresis, and the Minimum Inhibitory Concentration for fourteen antibiotics, including carbapenems was evaluated to define the resistance profile. PCRs were developed to detect genes coding for carbapenemases of class A (KPC, GES), B (VIM, IMP, NDM-1) and D (OXA-48), and plasmid-mediated AmpC betalactamases. K. pneumoniae isolates showed a multidrug-resistance profile: 73% was intermediate and 18% classified as resistant to imipenem, while 9% was resistant to meropenem. Ninety five percent of isolates was resistant to ceftazidime, ciprofloxacin and levofloxacin, the 14% and 5% observed as intermediate and resistant to amikacin. All cultures were resistant to the remaining antibiotics. Eight resistotypes were recognized, while PFGE identified 15 pulsotypes indicating heterogeneity of strains circulation in the hospital ward during the study period. Bla KPC, considered as the most important carbapenems resistance-related gene was not detected in any culture, but 90.9% harbored bla VIM, suggesting the production of VIM carbapenemase as the only mechanism for strains intermediate or resistant to carbapenems. The carbapenemases GES, IMP, NDM-1, OXA- 48 and AmpC beta-lactamases were not detected in any culture, which is in agreement with the sporadic reports from elsewhere in Italy. This study provides hitherto invaluable information for the implementation of surveillance of K. pneumoniae infections in nosocomial settings.