Graft-versus-host disease (GVHD) is the primary cause of non-relapse-related morbidity and mortality in patients who undergo hematopoietic stem cell transplantation. Dermatologic manifestations are common in both acute and chronic GVHD. In the acute setting, skin involvement often provides the first indication of GVHD and may progress to erythroderma and even skin necrolysis. In the chronic phase, skin involvement is extraordinarily polymorphic, potentially involves all layers of the skin and subcutaneous tissue, and presents in sclerotic and nonsclerotic forms. Management of cutaneous disease is challenging and ideally employs a multi-disciplinary approach and an understanding of the multiple medical issues facing patients with GVHD. The dermatologist plays a key role in caring for the patient with GVHD by providing an accurate diagnosis, determination of disease activity and response to treatment, and appropriate consideration of all available treatment modalities, including topical, systemic, and physical interventions (e.g. phototherapy, extracorporeal photopheresis). This chapter describes the cutaneous manifestations of acute and chronic GVHD and provides an evidence-based review of current treatment interventions for patients with GVHD skin disease.