In the present study, H-Mg-H···X···Y (X = Li+, Na+ and Y = C2H2, C2H4, C6H6) triads have been investigated at MP2/6-311++G(2d,2p) computational level to characterise cooperative effects between hydride bonding and cation–π interactions. Molecular geometries, binding energies, cooperative energies and many-body interaction energies were evaluated. The diminutive energy values in triads with Li+ are larger than respective values in triads with Na+. The electronic properties of the complexes are analysed using parameters derived from the quantum theory of atoms in molecules methodology.