This review deals with all structurally characterized complexes that contain one or more metallocene(mono- or di-)carboxylate ligand. This includes transition-metal, main-group, lanthanide and alkaline earth metal complexes. The compounds are discussed in terms of their carboxylate binding modes, overall metallocene conformations, and geometries imparted on the metal to which they are bound as well as the geometries generated by their use as linking units in supramolecular assemblies. The electrochemical, optical, magnetic and catalytic properties generated by introducing this additional metal center (or centers) are discussed where it is relevant. The review covers the literature up to early 2003 and most references are within the last five years.