Probiotics are live microbial feed supplements, which have an effect on the host animal by means of enhancing its intestinal microbial balance. A probiotic is a culture of a single bacterial strain, or a mixture of different strains, with the aim of eliminating the colonization of pathogens in the gastrointestinal tract of poultry. The main sources of probiotics in poultry are strains of microorganisms such as Lactobacillus, Enterococcus and Bacillus and fermented dairy products like yoghurt, cultured buttermilk and cheese. A good probiotic is characterized by its ability to exert a beneficial effect on a host, resistance to low pH and bile salts, adhere and colonizing of the intestinal epithelium, non-pathogenic to host and produces antimicrobial substances towards pathogens. It also... boosts immune responses, improves the growth performance and productivity of poultry and increases the quality of meat and egg. Thus, probiotics are considered to fill the gap in the poultry industry due to diseases and antimicrobial resistance of pathogenic bacteria as well as environmental conditions that cause serious problems and economic losses in many countries. With current consumer preferences tending toward purchasing products from livestock grown without antibiotics and feed additive, the ingredients in this review paper presented the beneficial applications probiotic may have in poultry production.