Ti, Zr, Nb, and Ta are biocompatible elements. A Ti-15Zr-4Ta-4Nb alloy for medical implants is being developed. In terms of in vitro cytocompatibility, the new bone tissue response to the Ti-15Zr-4Ta-4Nb alloy determined through rat tibia implantation was equal to or better than that to the Ti-6A1-4V alloy. An acceptable level of biological response can be expected when this alloy is used appropriately because it consists of biocompatible elements and has excellent biocompatibility, corrosion resistance, microstructure, and mechanical and fatigue properties. Therefore, the Ti-15Zr-4Ta-4Nb alloy with a low metal release rate is considered advantageous for long-term surgical implants.