The geometries, electronic and magnetic properties of the trimetallic clusters FeAlAun (n = 1-6) are systematically investigated using density functional theory (DFT). A number of new isomers are obtained to probe the structural evolutions. All doped clusters show larger relative binding energies than pure Aun+2 partners, indicating that doping with Fe and Al atoms can stabilize the Au-n clusters. The highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps, vertical ionization potentials and vertical electron affinities are also studied and compared with those of pure gold clusters. Magnetism calculations demonstrate that the magnetic moments of FeAlAun clusters each show a pronounced odd-even oscillation with the number of Au atoms.