A number of local and integral topological parameters of the electron density of relevant bonding interactions in the binuclear molybdenum complexes [Mo2Cl8](4-), [Mo-2(mu-CH3CO2)(4)], [Mo-2(mu-CF3CO2)(4)], [Mo-2(mu-CH3CO2)(4)Br-2](2-), [Mo-2(mu-CF3CO2)(4)Br-2](2-), [Mo-2(mu-CH3CO2)(2)Cl-4](2-), [Mo-2(mu-CH3CO2)(2)(mu-Cl)(2)Cl-4](2-), and [Mo-2(mu-Cl)(3)Cl-6](3-) have been calculated and interpreted under the perspective of the quantum theory of atoms in molecules (QTAIM). These data have allowed a comparison between related but different atom-atom interactions, such as different Mo-Mo formal bond orders, ligand-unbridged versus Cl-bridged, CH3CO2-bridged, and CF3CO2-bridged Mo-Mo interactions, and Mo-Cl-terminal and Mo-Cl-bridge versus Mo-Br and Mo-O interactions. Calculations carried out using nonrelativistic and relativistic approaches afforded similar results.