The current book highlights simple information about types and properties of microplastics in addition to abundance and distribution in different environments. Also it covers some topics including sources of microplastics in different ecosystems including air, water, soil and organisms and displays varied transport mechanisms of microplastics to the marine environment through rivers, wind transport, sewage and wastewater. The book gives insight into methods of sampling process for water, sediment, soil, dust, air and biological samples. Preservation as an important step to keep the matrix weight and concentration was also discussed. Preparation of samples using physical and extraction techniques were also presented. The book attempts to introduce information about the toxicological effects of microplastics on terrestrial and aquatic ecosystems. Effect on aquatic ecosystem and its inhabitant of bacteria, algae, fish, bivalves and crustaceans in addition to carcinogenicity to human was extensively discussed. This book also aims to introduce mechanisms of mitigation strategies such as recycling, landfilling, incineration, and other treatment methods.