In this study the solid-particle erosion behaviour of solutionised, artificially aged (T6) and annealed specimens prepared from an extruded aluminium alloy AA2014 was investigated and an intercomparison was made. The samples were eroded in specially designed, solid-particle erosion test equipment at a 45 degrees impingement angle and 75 m/s impingement velocity by using 180-mesh garnet erodent particles. Microstructures of the solutionised, artificially aged and annealed samples from the AA2014 were obtained using a light microscope. Moreover, the Vickers hardness of the samples exposed to different heat treatments was measured in order to evaluate the erosion rates with respect to the ductility changes in the material. Additionally, the surface morphology images of the samples were taken before and after the erosion test using a scanning electron microscope (SEM). The results showed that the heat treatments dramatically affected the erosion rates of the samples. However, artificially aged samples caused decrease reduction of the erosion resistance of the AA2014 aluminium alloy. The solutionised alloy showed the best erosion resistance compared to the precipitation hardening (T6) and annealed samples. The effects of the microstructures and the hardness on the erosion behaviour of the different heat-treated specimens were discussed. Finally, SEM images of the samples were analyzed in detailed and the erosion mechanism occurring on the surfaces of the samples was discussed.