An icosahedral quasicrystalline phase was found to be formed in rapidly solidified Al–Pd–Mn alloys. The quasicrystalline structure was confirmed to have a superlattice structure of the simple icosahedral quasicrystal, similar to the face-centred icosahedral structure for Al–Cu–Fe quasicrystals. The intensity of the superlattice reflections increases successively with increasing Pd content, and hence Pd atoms seem to occupy predominantly the superlattice site rather than the fundamental lattice in the icosahedral structure.