Over the past two decades, the presence of so-called emerging contaminants in various environmental compartments around the world, such as water, sediments, soils and atmosphere, and in a wide variety of consumer products has become a major concern for society, public health authorities, industry (namely food industry and water sector) and the agricultural sector. Some of these substances are endocrine disruptors and others are proven carcinogens and mutagens. In particular, there is a growing concern about the presence of emerging contaminants in water resources. The list of substances and products is particularly long: pesticides, pharmaceuti-cals, drugs of abuse (including licit and illicit drugs), cosmetics, personal care prod-ucts, surfactants, cleaning products, industrial formulations and chemicals, food additives, food packaging, metalloids, rare earth elements, nanomaterials, micro-plastics and pathogens. Most of these substances are found not only in domestic wastewater and industrial discharges, but also in surface and ground water, and consequently in drinking water and food sources. Therefore, emerging contami-nants entering the aquatic compartment may cause known, unknown or suspected adverse effects on the ecosystems and/or human health. Many molecules have been classified in recent years as priority or priority hazardous substances, and thus, the industrial world and the municipal wastewater treatment plants are particularly con-cerned by the release of these substances by virtue of increasingly strict regulations. However, existing conventional municipal wastewater treatment plants and drinking water treatment plants were not designed for eliminating these new contaminants. In addition, most emerging contaminants are not yet routinely monitored either in industrial discharges or in the environment. From an academic point of view, emerging substances are also of great interest to the scientific community and receive special attention. The areas of research concern not only their effects on human health and their impact on environment, but also their sources, analysis and fate in the environment, as well as their remediation. Indeed, their behavior in the environ-ment and their effects on all living organisms remain largely unknown. Many sub-stances are difficult to remove by conventional water treatment processes. Thus, there is an intense research activity on all these topics. The objective of this chapter is to present a recent state of knowledge on emerging substances and their presence in the aquatic environment. After general considerations on emerging contaminants, the first part is focused on chromatographic methods coupled to mass spectrometry for their analysis and detection, and on detection of microplastics in water and sediment. The presence of alkylphenols, rare earth elements and nanoparticles in the aquatic environment is then discussed. Finally, examples of contamination described from around the world, from China to Portugal, Mexico, Colombia and Brazil, are presented.