This work discusses the theoretical definition and practical application of different approaches to metamaterial homogenization. The categorization of the various approaches is based on the final objective of the homogenization procedure, i.e. on the specific metamaterial behavior that is required to be mimicked by the equivalent homogeneous medium. This behavior can be concerned with scattering properties, dispersion equation or the structure of the supported fields. Attention is focused on metamaterials realized by the superposition of identical periodic planar surfaces, for which numerical results are presented to illustrate the different homogenization approaches. © 2013 EurAAP.