Necrotic Enteritis (NE) caused by the pathogenic bacterium Clostridium perfringens is the most common and financially devastating bacterial disease in the poultry industry. The ban imposed by the European Union on the use of an- timicrobial growth promoters to prevent and/or treat the NE has led to an increase in both the clinical and subclinical forms of the disease, causing a decrease in the production performances of chickens and, in the most severe cases, to an increase in mortality rate. Many predisposing factors can favour the colonization and proliferation of C. perfringens,threatening the health of birds. These predisposing factors include the alteration of gut microbiota, severe damage of the epithelial surfaces, and the alteration of the animals’ immune status. Thus, the need for a prophylactic use of probiotics arises to prevent or mitigate the disease. Many bacterial species have shown probiotic activity, such as the genera Bacillus, Lactobacillus, Bifidobacterium, and Entero- coccus. These microorganisms, as well as favouring the col- onization of the gastrointestinal tract by a beneficial micro- flora and promoting the correct development of chickens’ immune system, they also compete with pathogenic bacte- ria to hinder their proliferation. This competitive exclusion mechanism exercised by probiotics promises to be an effi- cient and effective solution to replace the use of antibiotics in poultry industry, promoting animal health and favouring their productive performances.