Book excerpt: Biodegradable polymers have experienced a growing interest in recent years for applications in packaging, agriculture, automotive, medicine, and other areas. One of the drivers for this development is the great quantity of synthetic plastic discarded improperly in the environment. Therefore, R&D in industry and in academic research centers, search for materials that are reprocessable and biodegradable. This unique book comprises 12 chapters written by subject specialists and is a state-of-the-art look at all types of polyethylene-based biocomposites and bionanocomposites. It includes deep discussion on the preparation, characterisation and applications of composites and nanocomposites of polyethylene-based biomaterials such as cellulose, chitin, starch, soy protein, PLA, casein, hemicellulose, PHA and bacterial cellulose.