In this chapter nutritional modulation of immune function, with specific focus on research work from the year 2000 to present, is outlined with respect to immune responsiveness and disease resistance. In order to assess immune enhancement, suppression, and balance, independent sections for vitamins (i.e., carotenoids and vitamin E), minerals (i.e., selenium and zinc), and amino acids (i.e., arginine and threonine) are presented. Further, consideration of other nutrients is given (e.g., vitamin D, manganese, and copper). In addition to nutrients, sections in this chapter also are concerned with the ingredients on immune modulation (i.e., fats, oils, wheat, rye, insect meal, algae meal, and alternatively processed oilseeds). A section on in ovo manipulation of embryo and subsequent chick immunity is presented. Studies assessing few immune parameters versus those assessing overall immune balance in the presence of challenges are discussed.