In Clinical Infectious Diseases, Deverick Anderson and colleagues, including Jennifer Han and Ebbing Lautenbach, describe the activities of the Antibacterial Resistance Leadership Group (ARLG) in the area of antibacterial stewardship. Antibacterial resistance is increasing globally and has been recognized as a major public health threat. Antibacterial stewardship is the coordinated effort to improve the appropriate use of antibiotics with the aim to decrease selective pressure for multidrug-resistant organisms in order to preserve the utility of antibacterial agents. To date, the ARLG has focused intensely on development of rapid diagnostic tests, which (when coupled with educational and institutional initiatives) will enable the robust stewardship that is needed to address the current crisis of antibacterial resistance. Additionally, the ARLG has also developed strategy trials to assess the feasibility of reducing antibacterial usage while preserving patient outcomes. The authors conclude that rigorous antimicrobial stewardship research and infrastructure is critical to addressing this issue.