Pursuing sustainable and environment-friendly materials has spurred a paradigm shift in composite materials, with an increasing focus on composite materials with natural fibers as reinforcement. An in-depth study of composites crafted from natural fibers and recycled polyethylene terephthalate (rPET) as matrix is presented in this comprehensive review. The cellulosic fibers offer an eco-friendly alternative to synthetic reinforcements with attributes such as high tensile strength, low density, easy availability in abundance at low cost, and biodegradability. When incorporated into composites, they improve the mechanical behavior, and there is less material consumption, making it preferable for lightweight applications. Conversely, using rPET represents an innovative step in addressing the environmental challenges of using traditional petroleum-based plastics. The rPET matrix, derived from the chemical recycling of used PET bottles, is a promising material for developing environmentally conscious composites. The discussion includes mechanical properties and extends to the durability behavior of these composites, evaluating their resistance to moisture, UV radiation, and temperature variations: durability, resistance to deterioration, and performance of the composite materials under actual situations. The review concludes by exploring current challenges and limitations, highlighting areas for future research and development