The emerging contaminants (ECs) refer to chemical compounds either naturally originated or synthetically modified having potential toxic effects to the environment. The ECs include different pollutants such as biocides, pesticides, pharmaceuticals (antibiotic, analgesics, and hormones) and personal care products (cosmetics, fragrances, and hygiene products). The ECs are considering the top priority pollutants by the European Union (EU) and the United States Environmental Protection Agency (US EPA). Among other materials, the carbon nanotubes (CNTs) are one of widely used materials for the removal of ECs applying diverse techniques of wastewater decontamination. The momentous advancement of these functional nanostructured materials has found to be cost-effective, reusable, smart materials for the application of ECs removal. The aim of this chapter was to explore the modification routes and advancement of functionalization of CNTs with other functional groups by the reported works. The possible mechanistic insight of ECs removal reactions was also evaluated applying different methods for decontamination reported in the past studies. This review will be significant sources of information of CNTs-based materials for the application of wastewater treatment especially ECs removal from wastewater and ultimate environmental remediation.