Nowadays an important concern in the world is the development of eco-friendlier materials, for example using renewable resources such as lignocellulosic materials and biopolymers. Polylactic acid (PLA) is the most used biopolymer due to its easy processing and interesting properties. Nevertheless, the PLA has some disadvantages such as high brittleness, low flexural strength and higher cost than other conventional polymers. These PLA drawbacks can be overcome combining the PLA with reinforcements such as inorganic or organic fibers to produce biocomposites. The characteristics of natural fibers like biodegradability, low cost, and good mechanical properties offer some advantages in comparison with inorganic fibers in order to maintain the biodegradable feature of the final material. However, the different polar character of the natural fibers and PLA produces an incompatible interphase that results in low mechanical properties. In this sense, a coupling agent was prepared by reactive extrusion with glicidyl methacrylate (GMA) and PLA using dicumyl peroxide as initiator. The GMA-g-PLA (10 wt%) was used to produce compatibilized PLA/agave fiber bicomposites (60/30 wt%) by extrusion followed by injection molding. The mechanical (flexural, tensile and impact) and thermal properties of compatibilized and uncompatibilized biocomposites were evaluated. The results showed that fiber addition to PLA decreases tensile (from 56 to 51 MPa) and flexural strength (from 86 to 72 MPa), while with the GMA-g-PLA inclusion these properties increased (66 MPa to tensile strength and 104 MPa to flexural strength). Additionally, flexural and tensile modulus of PLA also increased with the addition of agave fiber and GMA-g-PLA.