Bacterial resistance poses a major challenge to the development of new antimicrobial agents. Conventional antibiotics have an inherent obsolescence because they select for development of resistance. Bacterial infections have again become a serious threat in developed countries. Particularly, elderly, immunocompromised, and hospitalized patients are susceptible to infections caused by bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. These bacteria form chronic, biofilm-based infections, which are challenging because bacterial cells living as biofilms are more tolerant to antibiotics than their planktonic counterparts. Therefore, research should identify new antimicrobial agents and their corresponding targets to decrease the biofilm-forming capability or persistence of the infectious bacteria. Here, we review one such drug target: bacterial cell-to-cell communication systems, or quorum sensing.