The clinical use of metallic biomaterials was first made available several decades ago and has been evolved greatly ever since as metals offer remarkable versatility and reliability with relatively low cost. Metals and alloys have been used extensively as structural biomaterials for surgical devices and implants, including bone and joint replacements, dental implants, orthopedic fixations and stents, cardiovascular and neurosurgical devices. A favorable combination of high strength and resistance to fracture that metals provide warrants reliable long-term implant performance in major load-bearing situations. Compared to polymeric and ceramic biomaterials, metals also give good electro-conductivity that favors their use for enclose electrodes in artificial electronic organs. The processing and composition of metal and its alloy determine their microstructure and that in turn determine properties. To obtain desired performance of biomaterials in service, tremendous original research has been carried out to study surface modification and surface strengthening of metals, resulting in the development of a number of powerful techniques such as laser ablation, plasma and acid etching, surface functionalization, coating, ion implantation and grain refinement.