During the last decade, the efforts to combat multidrugresistant (MDR) microorganisms mainly focused on gram-positive bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. While a large number of hospitals have implemented more rigorous infection control measures, drug companies have developed novel antimicrobial agents to combat these bacteria, resulting in several new compounds with novel mechanisms of action, eg, linezolid and daptomycin (66). Paralleling the developments in gram-positive bacteria, infections caused by MDR gram-negative bacilli have become a growing problem (71). In a recent report the Infectious Diseases Society of America specifically addressed three categories of MDR gram-negative bacilli, namely, extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp., MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter spp.(70). Unfortunately, and contrary to what happened with gram-positive bacteria, no antibiotic from a new class has been developed specifically for MDR gram-negative bacilli. It might be argued that the glycylcycline tigecycline is an exception from the statement made above, but although this drug has in vitro activity against many MDR gram-negative bacilli, the drug was not developed specifically for the purpose of treating infections caused by such bacteria (64). Moreover, there are now a growing number of reports of cases of infections caused by gram-negative organisms for which no adequate therapeutic options exist (20). This return to the preantibiotic era has become a reality in many parts of the world (14, 55, 80). The present report aims at estimating the prevalence of infections due to MDR gramnegative bacilli, as well as the consequences with respect to mortality, hospital length of stay (LOS), and increased hospital costs.