Phthalates are esters of phthalic acid and are a group of chemicals of high environmental relevance due to their production rates and ecotoxicological potential. Phthalates are mainly used as plasticizers in PVC plastics, wherein many consumer products contain specific members of this family of chemicals. In this book, the authors present current research on the chemical properties and impacts on health and the environment of phthalates. Topics include phthalate contamination in two estuaries from the Basque Coast; bioaccumulation and intracellular signal modifications of in vivo and in vitro models of phthalate esters; DEHP behavior in contact with liquid food simulants, blood, saliva and soil; removal of phthalates from the environment; gas phase fragmentation reactions of phthalate ions; the effects of DEHP exposure on brain development; and phthalate toxicogenomics and health effects.