The real risk of lymphoproliferative disease in psoriatic patients has not yet been defined. Two explanations can be given for the occurrence of these malignancies: the broad immune activation typical of psoriasis and the administration of an immuno-suppressive treatment. A few studies describing the development of non Hodgkin lymphomas in psoriatic patients undergoing cyclosporine A have been published, but data about the occurrence of chronic lymphoproliferative disorders have never been reported. Here we describe the occurrence of hairy cell leukemia and Waldenstrom macroglobulinemia in two psoriatic patients treated with cyclosporine A. It remains unclear in our cases of chronic lymphoproliferative disease, as well as in the reported cases of psoriatic patients who develop lymphomas, whether psoriasis or the immunosuppressive treatment could play a role, although it is not possible to exclude a synergism between these factors.