Polyphenols are a widely distributed group of natural products found in fruits, vegetables, nuts, seeds, stems and flowers. Such compounds, especially dietary flavonoids and tannins, have been shown to exert antioxidant, antiinflammatory, anti-cancer and antibacterial effects and may have beneficial effects on human health. The antimicrobial activity of polyphenols has been widely studied and hundreds of publications reporting the antimicrobial activity of polyphenols have been recently published. In an era of increasing antibiotic resistance, the development of new strategies to fight bacteria is welcome. Further studies are needed to evaluate the therapeutic potential of polyphenols alone or in combination with currently available antibiotics.