Carbon nanotubes (CNTs) remain one of the most efficient reinforcing material for enhanced mechanical and electrical properties. In this study, the effects of multi-walled CNTs (MWCNTs) fillers on mechanical, structural, and electrical properties of polymethyl methacrylate (PMMA)/MWCNTs composites were studied. The PMMA/MWCNTs composites, containing varying MWCNTs concentration of 0.1, 0.3, and 0.5 wt%, were prepared by a solution casting method. The mechanical properties of the composites such as tensile strength, elongation, Young modulus, tear resistance, fracture energy, impact strength, and hardness were investigated. Results showed that the mechanical properties of the composites were enhanced significantly. At 0.5 wt% MWCNTs, the tensile strength, elongation, tear strength, hardness, fracture energy and impact strength increased by 397%, 567%, 89%, 27%, 12%, and 36%, respectively …