The diffusion of aluminum in ion‐implanted noble metal‐aluminum solid solutions has been measured using the ( p,&ggr;)‐resonance broadening technique. The investigated temperature ranges were 375–550, 275–425, and 158–350 °C for copper, silver, and gold and the activation energies obtained were 1.88, 1.28, and 0.72 eV, respectively. Only the activation energy of aluminum in copper corresponds in magnitude to the ’’normal impurity diffusion’’ generally found to be valid for solutes in the noble metals.