The chapter discusses the antibacterial properties of free fatty acids (FFAs), which are released from lipids and have diverse biological activities. FFAs primarily target the cell membrane, disrupting the electron transport chain and oxidative phosphorylation, thereby inhibiting bacterial growth. Their broad spectrum of activity, non-specific mode of action, and safety make them attractive as alternative antibacterial agents in medicine, agriculture, and food preservation, especially where conventional antibiotics are undesirable or prohibited. The review also highlights the potential for commercial and biomedical exploitation of FFA-based antibacterial agents, particularly those derived from natural sources. The introduction provides a background on the structure and biological roles of FFAs, emphasizing their amphipathic nature and the importance of their carbon chain length and saturation.The chapter discusses the antibacterial properties of free fatty acids (FFAs), which are released from lipids and have diverse biological activities. FFAs primarily target the cell membrane, disrupting the electron transport chain and oxidative phosphorylation, thereby inhibiting bacterial growth. Their broad spectrum of activity, non-specific mode of action, and safety make them attractive as alternative antibacterial agents in medicine, agriculture, and food preservation, especially where conventional antibiotics are undesirable or prohibited. The review also highlights the potential for commercial and biomedical exploitation of FFA-based antibacterial agents, particularly those derived from natural sources. The introduction provides a background on the structure and biological roles of FFAs, emphasizing their amphipathic nature and the importance of their carbon chain length and saturation.