Biomaterials research has gained considerable momentum recently. The development of technology and the changing human lifestyles have also changed human health needs. The developed materials for use in different areas like in medical products and living bodies have necessitated adding biocompatibility to the mechanical, physical, and chemical properties of these materials. This article is a review of the concept and evaluation of biocompatibility. It explains how biomaterials change with the development of technology, human changing lifestyles, and needs, and how these materials are developed with the same technology. It contains what biocompatibility is, the factors that affect biocompatibility, what can happen in case of low biocompatibility, and the standards and work plans required for tests such as hemocompatibility, genotoxicity, toxicokinetic, and immunotoxicology for biocompatibility..