Abstract: Immunity plays a key role in disease susceptibility. Immunomodulators are agents which specifically modulate immune system regulating immunity and disease resistance. In poultry it is specifically important as the growth, disease resistance, FCR, body weight gain production output mainly depends on the health and immunity of the chickens. Different types of immunomodulators are prebiotics, probiotics, vitamins, adjuvants, polysaccharides, herbs etc. Immunology has great potentials in prevention and treatment of various range of disorders for instance the various inflammatory diseases of skin, respiratory tract, gut, central organs and joints. The preliminary objective of immunomodulation is to improve host resistance to external and internal attacks by the microbes or other infectious agents. Immunomodulators can substitute many agents like antibiotics, antimicrobials etc. for the improvement of the immune system. They also enhance the qualities of feed and immune molecules enhancing all possibilities to fight diseases and maintain health homeostasis. Since, they are not popular and not included in the poultry feed on routine basis, more efforts should be made to popularize it.