The success of a biocompatible material is intrinsically linked to the improvement on its surface properties since the surface is to be in direct contact with the living system when the material is implanted. For example, it has been shown that, via in vitro cell cultures, factors such as surface roughness or porosity increase cell adhesion on the biomaterial. Consequently, recent research on the design and development of biocompatible materials for implants in living systems must be closely connected to surface modifications and coating manufacturing techniques. The present article describes biocompatibility of surface coatings using, as a point of reference, widely implemented tests, namely cell adhesion, cell viability, biomineralization and corrosion, as well as their fundamental methods.