We systematically review the literature on antibiotics approved by the Food and Drug Administration since 2015 or that are in development through phase III trials for the treatment of infections due to gram-negative organisms. The crisis of antimicrobial resistance creates a dire need for the development of novel antimicrobials with enhanced activity against resistant bacteria. Of the agents that are currently in the pipeline or recently approved, few are from new classes and most represent modifications of preexisting agents. There continues to be a lack of treatment options especially for infections caused by organisms that produce metallo-β-lactamases. Furthermore, there is a paucity of data investigating the efficacy of these new antimicrobials for treatment of infections due to multidrug-resistant organisms. This review outlines the antimicrobials in development for the treatment of infections due to gram-negative bacteria. There are various agents in development that seem promising, but more studies are needed to evaluate the efficacy of these agents in treating infections, especially those due to multidrug-resistant organisms. The development of new antimicrobials is critical to combat the crisis of antimicrobial resistance.