Extracorporeal photopheresis (ECP) is a treatment approach that combines leukapheresis with photochemotherapy and is derived from PUVA; with this procedure, nucleated cells such as lymphocytes and monocytes are extracorporeally irradiated with UVA light after photosensitization. ECP is an effective treatment modality with few side effects that in recent years has been expanded to treat a range of indications. It has been proven effective in the treatment of cutaneous T cell lymphoma and is being increasing used in other lymphocyte-mediated, autoimmune and inflammatory diseases that are associated with proliferation of autoreactive T cells.