With the emergence of antibiotic-resistant microorganisms, diseases that are unresponsive to drug therapy, and the appearance of individuals that are unable to respond to conventional vaccines, the development of antigenspecific antibodies for use in passive immunotherapy is, nowadays, a major concern in human society. Despite the most focused mammal antibodies, antibodies obtained from egg yolk of immunized hens, immunoglobulin Y (IgY), are an alternative option that can be obtained in higher titres by non-stressful and non-invasive methods. This large amount of available antibodies opens the door for a new kind of cheaper biopharmaceuticals. Nevertheless, the production cost of high-quality and/or high-purity IgY still remains higher than other drug therapies due to the lack of an efficient purification method. Therefore, in this work, three types of aqueous two-phase systems (ATPS) were studied constituted by polymers and Na2SO4, polymers, Na2SO4 and ionic liquids (ILs) as adjuvants and by Na2SO4 and ILs, as an alternative technique for the selective extraction, and thus purification, of IgY from egg yolk. According to the obtained results, the complete purification of IgY was not achieved in a single step procedure (with β-livetin being the major contaminant found). However, the results obtained reveal that ATPS using ILs as adjuvants allow the selective extraction of β-livetin for one phase and it is possible to purify the immunoglobulin if successive extractions are applied. Amongst the various ATPS evaluated, the improved results on the selective extraction and subsequent purification of IgY were obtained with ATPS consisting of polyethylene glycol (PEG) of low molecular mass and ILs with the anion dicyanamide.