This overview describes the different roles that borane and carbaborane clusters play in the assembly of coordination polymers and networks. The review uses data in the Cambridge Structural Database as a starting point to exempify the variety of 1D, 2D, and 3D-architectures that have been described featuring borane and carbaborane cages. The roles of these clusters range from 'space fillers' to rigid-rods (linkers) to connecting nodes. Even as 'space fillers', some clusters may play a critical role, for example, the templating effects of the spatially demanding [Co(C 2 B 9 H 11 ) 2 ] − cage. Arguably, some of the most important roles of carbaborane clusters are as scaffolds for the design of di-, tri-, and tetratopic multifunctional carboxylate linkers. These mimic arene-centred organic linkers which are well-established as linkers or connecting nodes 2D- and 3D-networks. The different spatial demands of the cluster- versus arene-cores may lead to significant differences in the resulting architectures. Finally, the role of three-centre two-electron B-H-M interactions in the assembly of polymeric structures in the solid state is illustrated, mostly with M = alkali metal or silver(I)