It is imperative to control the interactions between biomaterials and living tissues to optimize their therapeutic effects and disease diagnostics. Because most biomaterials do not have the perfect surface properties and desirable functions, surface modification plays an important role in tailoring the surface of biomaterials to allow better adaptation to the physiological surroundings and deliver the required clinical performance. This paper reviews recent progress pertaining to the surface treatment of implantable macro-scale biomaterials for orthopedic and dental applications as well as micro- and nano-biomaterials for disease diagnosis and drug/gene delivery. Recent advances in surface modification techniques encompassing adsorption, deposition, ion implantation, covalent binding, and conversion have spurred more expeditious development of new-generation biomaterials.