Chickens have the potential to be used to complete the spectrum ofrnanimals used for antibody production. IgY technology is a fast developing fieldrnand we have tried to cover most of its aspects. IgY technology was that, oncernaccepted and widely used, the technology will offer alternatives and solutionsrnto science, to medicine and to society as a whole. In particular, because ofrnthe increasing resistance of microorganisms to antibiotics, research on allrnaspects related to the development of specific IgY against pathogenicrnmicroorganisms will have to be intensified. IgYs can be used both in veterinaryrnmedicine and in human medicine. This review offers summarized information aboutrnIgY technology and the use of these antibodies against various infectiousrndiseases.