The objective of this work is to develop new composites using PLA as matrix, by adding as fillers modified cellulose nanofibers and nanocrystals obtained from agricultural waste of a highly fibrous plant (Agave tequilana) in order to give value added applications to an undervalued material. On the other hand, PLA properties require improvements to compete with other plastics, making important the exploration of new surface modifications in polymer reinforcements in order to increase mechanical and hydrophobic properties of PLA and to enhance the interaction between nano fillers and the matrix, avoiding the formation of dislocations in the interaction surface. Two different surface modifications on two cellulose nanoparticles (CNF and CNC) were evaluated to determine the improvements that these modifications provide to the cellulose surface, they were also compared to raw blue agave bagasse and to bleached pulp to analyze if working on nano-scale was relevant.