The value of dietary exogenous enzymes in promoting growth and efficiency of feed utilization is well recognized in poultry industry. In a case of high-cost yellow corn, several feed producers are choosing to replace yellow corn with other ingredients that have lower nutritional value like triticale, wheat, barley or sorghum. These crops are rich in non-starch polysaccharides (NSPs), and there is an inverse relationship between the content of NSPs in the feed and its nutritional value. Dietary supplementation of enzymes can enhance the nutritional value of crops containing high contents of soluble NSPs. Numerous studies have shown that supplementation of exogenous enzymes in wheat, barley, sorghum or triticale-based rations can improve performance of poultry to a level compared to that obtained by corn-soya-based rations. Naturally, the gastrointestinal tract of poultry produces enzymes to aid the digestion of nutrients. However, the birds do not have enough enzymes to digest fiber completely and need some commercial exogenous enzymes in the diets to improve the digestion. Enzyme is a biological catalyst composed of proteins, amino acids with minerals and vitamins. The advantages of using commercial enzymes in poultry feeds include improved productive performance and feed utilization, minimized environmental pollution due to reduced nutrient of manure. The present review covers the information on enzyme uses and its applications in poultry production. Furthermore, this article demonstrates that the exogenous enzymes are very important factors in the study of metabolic and physiological mechanisms. Such data will improve our understanding regarding the role of commercial enzymes in poultry feeds.