Effective antibiotics for severe infections caused by resistant bacteria are needed urgently. The speed with which bacteria develop resistance to antibiotics, in contrast with the slow development of new drugs, has led some experts to warn of a “post-antibiotic era.” Compared to the pace 30 years ago, few novel antibiotics have been added to pharmacy shelves in recent years, and the R&D pipeline will, at best, continue its slow trickle of new agents. Judicious use of the antibiotics currently available—particularly through better infection control in hospitals and more rational prescribing—may help conserve their effectiveness. However, even if we improve these practices, resistant bacteria will continue to develop, and new and better drugs will be needed.