Antibacterial research over the past 50 years has been focused on meeting medical needs caused by infectious, life-threatening pathogens. In spite of the introduction of a variety of antibacterial agents in multiple unrelated drug classes, resistance continues to emerge. The pharmaceutical industry must respond to these clinical challenges by bringing forward a stream of new agents with antibacterial activity against resistant bacteria. Although the projected growth of the anti-infective area may not be as large as for some therapeutic areas, development advantages for these agents include their higher predictability for success, well-defined biomarkers, shorter clinical trials, and shorter duration of therapy leading to fewer long-term safety concerns. Anti-infectives are still attractive commercially, representing the third largest therapeutic area in terms of worldwide sales of 45 bn dollars, with growth predicted at least through 2010, particularly for the hospital-related products. Finally, companies that conduct anti-infective research demonstrate their social responsibility by developing agents to treat patients with acute and potentially fatal illnesses.