Divalent dibismuthanes R4Bi2 with a Bi–Bi single bond and monovalent dibismuthenes R2Bi2 containing a Bi–Bi double bond have been prepared in the last decades mainly by use of sterically demanding organic (mainly C- and N-based) and silyl substituents (kinetic stabilization) and/or by use of donor-functionalized substituents (electronic stabilization). In recent years, sterically demanding L1(X)M ligands containing electropositive group 13 metals (M = Al, Ga, In) have been used for the stabilization of such compounds. Dibismuthanes and dibismuthenes often suffer from their rather low Bi–Bi bond energy and their sensitivity toward air and light, which makes their isolation often challenging. The same is true for neutral bismuthanyl radicals R2Bi·, which have only been recently structurally characterized for the first time, as well as dibismuthene radical anions, respectively. This chapter summarizes the synthesis and solid-state structures of these interesting metal-metal bonded species and their fascinating reactivity, which ranges from the formation of Lewis acid-base adducts over radical formation to the synthesis of larger cluster-type complexes, will be highlighted.