Synthetic plastics have several concerns for the environment, such as their impact on climate change, their long degradation time, or their degradation to microplastics that threaten animal life in the sea. The application of natural fibers as reinforcement in synthetic polymeric matrixes has several advantages in properties such as low density, lower cost of production, biodegradability, and a reduction of the environmental impact in the polymer industry. In this study, the Ecuadorian Guadua Angustifolia Kunth fiber was extracted and treated physically and chemically for its use as reinforcement in composite preparation. Maleic anhydride was used as a coupling agent to improve the interaction between the natural fiber and the low-density polyethylene (LDPE) polymeric matrix. The composite production was done using different bamboo particle loading (1-5% w/w) at a constant particle size (150 μm). Chemical, physical, and mechanical properties were evaluated to characterize the fiber and biocomposites. The chemical treatment of the fiber with 2% of NaOH showed a reduction of the lignin content confirmed by Fourier-Transform infrared spectroscopy. A total of ~39% mass loss related to the lignin, waxes, and other organic content was reached. In addition, a reduction in the density from approximately 0.87 to 0.66 was shown when increasing the content of bamboo in the composite. In the same way, the crystallinity was reduced by 3%. The composite with 1% bamboo presents a tensile strength of 10,66 MPa. The use of bamboo fiber in the biocomposites reduces the global warming potential concerning the increasing amount of fiber.