Initially considered as a sub-class of ionic liquids, eutectic mixtures are formed by mixtures of low cost, often biodegradable Lewis or Bronsted acids and bases. Eutectic mixtures have gathered a growing scientific interest by the academic and industrial communities as they are interesting for many applications ranging from metal processing to biomass treatment or pharmaceuticals. This volume gathers contributions by some of the most active research groups in the world using eutectic mixtures for applications in separation, extraction or pharmaceutical and medical applications. The different contributions aim at a large overview of the field for these particular applications by reviewing literature data and presenting ground breaking research in the different fields.