This issue of Medical Clinics of North America brings the physician up to date on the newest agents for antibacterial therapy. New drugs are covered, as well as new approaches. Topics include the newer fluoroquinolones; epidemiology, molecular mechanisms, and clinical management of pathogens resistant to antibacterial agents; current use for old antibacterial agents, including polymyxins, rifamycins, and aminoglycosides; topical antibacterial agents; newer beta-lactam antibiotics, including doripenem, ceftobiprole. ceftaroline, and cefepim; the use of antibacterial agents in renal failure; antibiotics for gram positive bacterial infections, including vancomycin, teicoplanin, quinupristin/dalfopristin, oxazolidinolones, daptomycin, telavancin, and ceftaroline; as well as macrolides, ketolides, and glycylcyclines, including azithromycin, clarithromycin, telithromycin, and tigecycline.