The therapeutic choice in treating Pityriasis Rubra Pilaris (PRP) is difficult, particularly in extensive erythrodermic forms and in those characterized by a strong tendency to recur. None of the therapeutic modalities till now employed have been proved to be resolutive. The curative potential of photochemotherapy in the treatment of PRP has been particularly uncertain. Here a case of recurrent PRP in an adult female subject is reported. The disease covered about 90% of the skin surface and was treated by means of photochemotherapy (total dose: 179.56 J/cm2). A complete remission of the disease has been obtained and is still maintained nine months after the end of the treatment.