Biocomposites from polylactic acid (PLA) and olive solid waste (OSW) were melt-blended with core-shell acrylate rubber particles (ACR) in order to enhance the thermal stability upon melt processing and the mechanical performances of these biocomposites, thereby expanding their area of application. Dynamic mechanical analysis indicated that the ACR particles imparted more flexibility to the PLA/OSW biocomposites and thermal analysis showed that the incorporation of ACR significantly restrained the ability of the PLA chains to crystallize. The values of complex viscosity and storage modulus were significantly increased with the introduction of ACR. These results could be assigned to the entanglements between the PLA chains and those of the ACR shell, giving rise to a physical network that limited the segmental mobility of PLA and induced a high melt elasticity. Mechanical tests revealed that the elongation at break and the impact strength of the biocomposites were considerably improved. Moreover, morphological observations showed a clear adhesion enhancement between the PLA matrix and the OSW fillers in the presence of the ACR additive. POLYM. ENG. SCI., 58:894-902, 2018. (c) 2017 Society of Plastics Engineers