Biodegradable polymers have attracted significant attention for their highly versatile processing and manufacturing alternatives for bone filling applications. However, several issues regarding mechanical performance are yet to be solved prior to allowing maximal loading transfer between adjacent tissue and the implanted biomaterial. An issue that could be overcome by fine tunning their mechanical stiffness through incorporation of natural lignocellulosic fibers such as cocoa bean shells (CBS). Hence, this study presents the fabrication by compression molding of Poly(lactic acid) (PLA) and CBS composites for their potential use as bone fillers. The obtained materials were characterized in terms in terms of mechanical performance and cytotoxicity in vitro. The PLA/CBS composites showed an increase in stiffness as a function of the CBS content. However, no statistically significant changes (p < 0.05) were observed for the three-point bending flexural properties of composites with CBS content below 10%wt. In addition, the cell viability of Vero cells in the presence of the composites was above 94% after 24 h, demonstrating potential in vitro biocompatibility. The obtained results indicate that a suitable route was developed for manufacturing filled biocompatible composites with tunable mechanical properties comparable to those reported previously for bone fillers.