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, 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.