In this research, Si₃N₄ nanoparticles were coated on an anodized Ti-6Al-4V surface using electrophoretic deposition, aiming for improved bioactivity, biocompatibility, and antibacterial properties for biomedical applications. TiO₂ nanotubes were first formed on the Ti-6Al-4V substrate at various times of 1, 2, and 4 h under a constant voltage of 40 V. The optimized anodized surface, defined by corrosion, mechanical, and topographical evaluations, was electrophoretically coated with Si₃N₄ nanoparticles. The morphological and microstructural implications were investigated by field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Results demonstrated that the 4 h-anodized samples showed the highest roughness and the closest bone-like mechanical properties in terms of hardness and elastic modulus. Results also confirmed that surface functionalization with Si₃N₄ nanoparticles appears very promising in terms of biomedical properties. Si₃N₄ association with the anodized surfaces resulted in improved antibacterial activity and cell viability. Also, Si₃N₄–functionalized anodized surfaces showed promising bioactivity, confirmed by the formation of hydroxyapatite crystals, when samples were immersed in the stimulated body fluid (SBF) solution. Overall, the surface functionalization of anodized surfaces with Si₃N₄ nanoparticles appears to have promising positive implications for the biomedical properties of anodized surfaces, which are often supposed to be used in orthopedic applications.