The markets for applications of biocomposites are expanding internationally. A biocomposite is a material made from a mixture of natural fibers and a thermoplastic polymer to obtain a product having some characteristics of both resources: (a) filler reinforcement (plus wood-like appearance of wood plastics) and (b) plastic performance in wet conditions. Wood–polymer composites (WPCs) are used mainly in four different sectors of materials applications: building, construction, automotive, and marine infrastructures. Current major scientific and technological efforts are focused on increasing the bio-based carbon content and minimizing environmental impacts associated with the use of polymeric materials. However, bio-based composites can create problems at the end of their lives. The current recycling streams are not suited to such materials. That is why the focus is increasingly on “eco-friendly” materials such as composites based on natural or synthetic biodegradable polymers and fillers such as starch, vegetable fiber, or wood flour. The most studied WPC-based biodegradable matrix systems are composites based on polylactic acid (PLA). Many studies deal with the mechanical properties and the inclusions of additives to improve the effects of reinforcing fillers. However, very few studies are devoted to the durability of these new biocomposites during their service life.