In this work, we have used density functional theory with PW91PW91 functional to analyse the structures, relative stabilities and electronic properties of small bimetallic neutral and charged Au (n) Al-2 (n = 1-5) clusters. The results reveal that doping with two Al atoms can significantly affects the geometries of the ground-state Au (n+2) (n = 1-5) clusters. The relative stabilities of the clusters were investigated on the basis of average binding energies, fragmentation energies and second-order difference of energies. The electronic properties are calculated using vertical ionization potential, vertical electron affinity values and these parameters show even-odd alternation phenomenon. The nature of bonding interaction is also investigated for the first time in Al-doped clusters using Bader's quantum theory of atoms in molecules which indicates the presence of covalent bonding in the studied clusters. The population analysis reveals the transfer of electrons from Al to Au atoms which is responsible for the enhance stability of doped clusters.