In the United States more than 100,000 people are living with solid organ transplants. The intense immunosuppressive regimens necessary for prolonged survival of allografts significantly increase the rates of both internal and cutaneous malignancies in recipients of solid organ transplants. Skin cancer is the most common cancer in patients after transplantation. Because of the early onset and high tumor burden in transplant recipients, dermatologists have significant challenges in managing the treatment of these patients. This article describes the epidemiology and clinical presentation of skin cancer during posttransplantation immunosuppression, discusses pathogenic cofactors, and reviews the optimal management for mild and severe skin cancer in transplant recipients. (J Am Acad Dermatol 2002;47:1-17.) Learning objectives: At completion of this learning activity, participants should understand the following: (1) the epidemiology of skin cancer in organ transplant recipients, (2) cofactors implicated in the pathogenesis of accelerated carcinogenesis in this patient population, and (3) the principles of preventive education and prophylactic therapy as well as the surgical management of the various tumors occurring in these high-risk patients.