<p>Due to their excellent properties polyurethane cellulose and their composites have become widely used in previously unimagined areas. Given the fast-increasing consumption in recent years the demand for advanced polyurethane- and cellulose-based composites is rapidly growing. Accordingly this Special Issue seeks to showcase research papers short communications and review articles focusing on innovations in polyurethane- and cellulose-based materials including material synthesis modification and engineering.</p>