Nanotechnology has revolutionized various scientific and engineering fields, including materials science. In this investigation, the focus is on examining the influence of titanium nanoparticle size on the mechanical and physical properties of metal. Incorporating nanoparticles into metal matrices presents an exciting opportunity to enhance material performance through size-dependent effects. Titanium nanoparticles have been chosen as the primary focus due to their unique properties and extensive applications. To assess the impact of nanoparticle size on mechanical properties, a series of experiments were conducted involving the production of metal composites with varying sizes of titanium nanoparticles. Mechanical properties, including yield strength and hardness, were measured using standard testing methods such as tensile testing and nanoindentation. The results indicate that smaller titanium nanoparticles contributed to improve mechanical properties, increased yield strength and hardness compared to the bulk metal. Additionally, the investigation explored the effects of titanium nanoparticle size on the physical properties of the metal composite. Thermal conductivity and coefficient of thermal expansion were measured to evaluate the thermal behavior of the composites. The findings demonstrate that the incorporation of titanium nanoparticles influences thermal conductivity and coefficient of thermal expansion, with variations that depend on nanoparticle size.................. Keywords:....... Nanotechnology, Titanium Nanoparticles, Mechanical Properties, Physical Properties, Metal Composites.