Bioactive peptides are specific protein fragments that positively impact the body's function or condition and ultimately may influence health. These peptides are inactive within the sequence of the parent protein and can be released during proteolysis or fermentation. They may exert a number of different activities in vivo, affecting cardiovascular, endocrine, immune and nervous system in addition to nutrient utilization. Hen eggs have traditionally been recognized as an excellent source of protein, vitamins and minerals. Research in the past decade, however, has produced a substantial amount of evidence indicating that hen egg proteins and peptides may exert several diverse biological effects, above and beyond fulfilling basic nutritional requirements. Several biological activities have now been associated with hen egg proteins, including novel antimicrobial activities, immunomodulatory, anti-cancer, and anti-hypertensive activities, highlighting the importance of hen egg proteins in human health, and disease prevention and treatment. Continued research to identify new and existing biological functions of hen egg proteins and their derivatives will help to define new methods to further improve the value of eggs, as a source of numerous biologically active compounds with specific benefits for human and animal health, and secure their role in the therapy and prevention of chronic and infectious disease.