Current treatment of chronic graft-versus-host disease (cGVHD) with prednisone (PSE) alone or with added cyclosporine or tacrolimus still has a very high failure and complication rate, and new treatment approaches are needed for both primary and salvage therapy. Mycophenolate mofetil (MMF) is an immunosuppressive agent currently in use for acute graft-versus-host disease prophylaxis. To determine whether MMF had activity in the treatment of cGVHD, we added MMF to standard cyclosporine, tacrolimus, and/or PSE as salvage/second-line (n = 24) or first-line (n = 10) therapy in 34 patients. Nine (90%) of 10 patients receiving first-line and 18 (75%) of 24 receiving second-line MMF therapy responded. Twelve (35%) patients had a complete remission, 15 (44%) had a partial remission, 5 (15%) had stable disease, and only 2 (6%) had progressive disease. Out of 30 patients receiving PSE, 22 (73%) were able to decrease PSE doses (median decrease of 50%; range, 25%-100%). With a median follow-up of 24 months (range, 6-28 months), 29 (85%) patients are alive. Three patients had to discontinue MMF because of abdominal cramps within 3 months of starting treatment. These data suggest that MMF is an active, well-tolerated agent in the treatment of cGVHD and may have a beneficial effect on the survival of patients with this complication. © 2005 American Society for Blood and Marrow Transplantation.