Chalcones, containing an α,β-unsaturated ketone fragment, are an important pharmacologically active agents because of their diverse mechanisms. This review provides an update on the recent developments (2009-2019.3) in the antibacterial activity of natural and synthetic chalcones. Moreover, the structure-activity relationships and mechanisms are also carefully summarized which will provide some important guidance for design and synthesis in future. This comprehensive and critical review will be helpful for medicinal chemists to develop more candidate antibacterial agents.