Metal-molecule clusters, V-n(benzene)(m), Co-n(benzene)(m), and their ions, were synthesized by the reaction of laser-vaporized vanadium atoms with benzene vapor. Both neutral and cationic V-n(benzene)(m) clusters exhibit magic number behavior at m = n + 1 (n = 1 - 5), which was explicable in terms of multiple-decker sandwich structure.