Chronic graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplantation and the leading cause of death more than 2 years after transplantation.During the past 30 years survival of patients with chronic GVHD has not improved and steroids remained the most often used therapy. Extracorporeal photoimmunotherapy (ECP)has shown to be efficacious in patients with GVHD. We propose a phase II study to evaluate the safety and efficacy of ECP as adjunct first-line therapy in patients with newly diagnosed chronic GVHD of liver or lungs and need for systemic immunosuppression defined according to the NIH consensus criteria.