This chapter discusses thermoplastics and thermosets. Recycling of plastics is one method for reducing environmental impact and resource depletion. Recycling is the final result of the intermediate stages of collection, sorting by type, and processing of polymers. Recycling plastics encompasses four phases of activity, namely collection, separation, processing, and manufacturing and marketing. There are various stages of recycling: collection, cleaning, sorting, and size reduction. After processing, plastic waste materials are further subjected to various techniques such as extrusion, injection molding, blowmolding, and filmmolding. Many different recycling techniques have been studied during the last two decades, such as mechanical processes, pyrolysis and other thermal processes, and solvolysis. Composites are generally considered high-value, high-performance materials that are employed in producing end products of high net worth. Recycling or reuse makes increasing sense economically as well as environmentally, and recent trends demonstrate a substantial increase in the rate of recovery and recycling of plastic wastes.