An expansion anchor comprising a tubular body, which extends along a longitudinal axis and is structured so as to have a head at one end, adapted to be engaged inside a hole obtained in a wall; the head comprising a deformable body made of a first plastic material having a predetermined mechanical rigidity, and at least one longitudinal rigid insert, which is firmly integrated in the deformable body and is made of a second plastic material having a higher mechanical rigidity than the mechanical rigidity of the plastic material of the deformable body itself.