Biobased and biodegradable polyactide (PLA)-pine wood flour (PWF) composites were investigated as a means to reduce the overall material cost and tailor the material properties. The composites were prepared using a kinetic-mixer and an injection molding machine. The tensile modulus on the PLA-PWF composites increased with the PWF content whereas the toughness and strain-at-break decreased. The tensile strength remained the same irrespective of the PWF content (up to 40%). The storage modulus also increased with the PWF content. Additionally, composites containing PWF treated with silane showed higher storage modulus than those without the silane treatment. The area integration underneath the tan delta peaks decreased with increasing PWF. The degree of crystallinity of the PLA-PWF composites increased significantly with the PWF content. Furthermore, the treatment of PWF with silane had a positive effect on its nucleating ability, as treated PLA-PWF composites showed higher crystallinity compared with their untreated counter-parts. The morphology of the fracture surfaces were studied using a scanning electron microscope. Finally, a Halpin-Tsai analytical model to predict Young's modulus of PLA-PWF composites was presented to compare the theoretical results with that of experimental results.