Hospital-acquired bacterial infections pose a formidable challenge for healthcare providers, as patients often need to be treated empirically, at least initially, although delay of appropriate initial antimicrobial therapy is known to increase morbidity significantly and to increase mortality among affected patients. This elevated risk is compounded by the presence of antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum beta-lactamase-producing Enterobacteriaceae, Escherichia coli and Klebsiella pneumoniae. Prompt initiation of treatment with an appropriate antimicrobial agent that is active against both Gram-positive and Gram-negative organisms is prudent for patients with nosocomial infections. As the continued usefulness of vancomycin comes into question, the number of alternative agents that provide efficacy equal to that of vancomycin remains limited. The development of novel and effective alternative agents, such as tigecycline, is therefore important.