The increasing occurrence of bacterial diseases in freshwater aquaculture has become a major concern due to the substantial economic losses affecting the fisheries sector. Bacteriocin-producing probiotics have emerged as a promising approach for reducing fish mortality and disease incidence, as they are generally regarded as safe and produce fewer side effects compared to conventional treatments. In aquaculture, it is crucial to understand the mode of action by which bacteriocins are effective against pathogens in order to utilize them as a biopesticide, particularly as a prophylactic biopesticide. Antibiotics, chemotherapy and vaccination are usually the techniques used, but they may have negative effects on cultured organisms and the aquatic environment and are not often used in field conditions. These bacteriocins are environmentally friendly alternative to chemical treatment in the freshwater aquaculture industry for bacterial disease management if properly up used. Bacteriocins and their modes of action against the major pathogens of the aquaculture industry are emphasized.