Polymethyl methacrylate (PMMA) serves as sealing material in securing the implant and distributing the load between the implant and bone. Fast polymerization and speedy patient recovery after surgery are the main benefits of using PMMA bone cement. Considering PMMA for orthopedic applications, the mechanical properties and biocompatibility studies are important. In this study, Simplex P bone cement is reinforced with carboxyl functionalized multiwall carbon nanotubes (MWCNTs-COOH) to evaluate compressive strength, Shore D hardness, and in vitro biocompatibility properties. MWCNTs are added to the PMMA powder in different amounts using a geometric dilution technique. The PMMA/MWCNT nanocomposite is prepared with MWCNTs varying from 0.1 wt. % to 0.7 wt. %. The compressive strength and Shore D hardness values increased to a maximum of 69.21% and 4.84%, respectively for 0.3 wt. % loading. The in vitro cytotoxicity studies on MG-63 cells show a percentage cell viability of 81.37 % for 0.3 wt. % and 83.25 % for 0.7 wt. % MWCNTs loading. Hemolysis studies on human B+ve blood exhibited a low hemolytic potential of 15.12% for 0.3 wt. % and 16.38% for 0.7 wt. % MWCNTs loading on human RBCs. It is concluded that the prepared PMMA/MWCNT nanocomposites are found to have enhanced mechanical properties compared to Simplex P bone cement.