Antibiotics have been used for many years as growth promoters. They contribute to build the immunocompetence (i.e. ability of the body to produce a normal immune response following exposure to an antigen) of birds against infectious diseases and as growth promoters. Antibiotics have been widely used as growth promoters in the field of animal production since 1940s. There is a hypothesis that is effect is brought about by dynamic biological interaction with the micro-flora in the intestine. In 1951, the United States Food and Drug Administration approved the use of antibiotics as animal additives to prevent disease in general and, in some cases, to improve efficiency without veterinary prescription. In the 1950s and 1960s, each European state approved its own national regulations about the use of antibiotics in animal feeds. However, using antibiotics may develop bacteria resistant to these drugs. Accordingly, the use of antibiotics has been minimized and replaced by effective dietary supplements such as probiotics and/or prebiotics that are claimed to enhance growth and positively modulate the immune response. The current review paper sheds light on the benefits of using probiotics and/or prebiotics in poultry feed versus the risk of using antibiotics and the mechanisms by which they exert their effects, as well as the economic analysis of using these beneficial additives in poultry feed.