The luminescence properties of the heteroleptic [Re(CO)2(P^P)(N^N)]+ complexes with the bidentate P^P – cis-1,2-bis(diphenylphosphino)ethene and different N^N – α-diimines ligands have been studied in acetonitrile solutions at room temperature and in methanol/ethanol (1: 1) glasses at 77 K. The investigated complexes exhibit the metal to ligand charge-transfer (MLCT) phosphorescence with the emission characteristics strongly affected by the nature of coordinated α-diimine N^N. Depending on the α-diimine attached to the [Re(CO)2(P^P)]+ core, the room-temperature values of emission wavelength λem, quantum yield ϕem, and life-time τem vary in the range of 580–630 nm, 0.022–0.23, and 0.25–22 μs, respectively. The lowering of the measurement temperature leads to hypsochromic shift of the emission maxima (by 30–60 nm) and lengthening the emission life-times (up to 52 μs). The observed changes in the λem, ϕem, and τem values have been explained within the Mulliken-Hush formalism by invoking the electronic interactions between 3*LC (lowest excited triplet of N^N ligand) and 3*MLCT states as well as the spin-orbit interactions between 3*MLCT and 1*MLCT species, respectively. All quantities necessary for the description have been accounted from the analysis of the absorption 1 *MLCT ← S0 and emission 3*MLCT → S0 charge transfer processes. It is also demonstrated that the radiative kr and non-radiative knr decay rate constants of the excited 3 *MLCT states can be interpreted within the same set of parameters. The investigated complexes have been found to be similar to their [Re(CO)3(N^N)(Cl)] analogues but some intrinsic differences distinguish two compared series.