Recent developments in the field of metal-rich low valent metal complexes with gallium(I)/zinc(I) ligands and their structural features are reviewed together with related theoretical calculations. Some emphasis is given to sterically encumbering NHC analogous ligands as well as the naked ions E +. The chemistry of organo Zn(I) ligands at transition metals is reviewed in the light of the recently discovered synthetic approach via suitable organo Ga(I) complexes as starting materials. © Springer-Verlag Berlin Heidelberg 2010.