Microplastics accumulate in the environment through numerous entry pathways, with wastewater discharge being one of the major sources. There are multiple methods for identifying, characterizing, and treating microplastics in wastewater; however, some microplastics still escape into the environment with the sludge and final treated effluent. Additionally, microplastics can adsorb toxic contaminants such as heavy metals, which can then bioaccumulate through different levels of the food chain. As a result, wastewater treatment plants act as hubs for toxic contaminants, concentrating microplastic-associated pollutants. These toxic wastewater microplastics (WWMPs) can enter both aquatic and terrestrial environments, posing significant threats to a wide range of organisms. In the environment, variety of organism from soil invertebrates to human in the land and plankton to whales in the water expose to microplastics causing both physical (e.g., tissue damage, blockages, etc.) and chemical damage (e.g., oxidative stress, genotoxicity, etc.). Ingestion of microplastics often leads to their accumulation and blockage within the digestive systems of exposed organisms. Also, these microplastics make alterations in metabolic pathways of microbes, plants and animals. While wastewater treated sludge is sometimes used as fertilizer to support plant growth, it can degrade soil structure and properties, harm beneficial soil bacteria, and ultimately affect soil health. The major challenges in mitigating wastewater microplastics are the lack of comprehensive research and advanced technology for the complete removal of microplastics from treatment plants and sources. Accordingly, this chapter further highlights the feasible advanced wastewater remediation strategies, relevancy of the environmental policies, legal enforcements and explores future directions for management and mitigations of microplastics in wastewater.