A 48-year-old man with hepatitis C virus (HCV) cirrhosis complicated by hepatocellular carcinoma underwent liver transplantation. His course was complicated by fever, diarrhea, abdominal pain, and pancytopenia. He developed a diffuse erythematous rash, which progressed to erythroderma. Biopsies of the colon and skin were consistent with acute graft-versus-host disease. Donor-derived lymphocytes were present in the peripheral blood. The patient was treated with corticosteroids and cyclosporine; however, he had minimal response to intensive immunosuppressive therapy. Extracorporeal photopheresis was initiated as a salvage therapy. He had a dramatic response, and his rash, diarrhea, and pancytopenia resolved. He is maintained on minimal immunosuppression 24 months later.