As survival rates for hematopoietic stem cell transplantation (HSCT) have grown in the past two decades with improved management of acute toxicities, 1-2 attention to long term complications has become more salient to clinicians, researchers, and survivors themselves. Sexual dysfunction has been defined as one of the most common long term issues following HSCT. 3-4 Prospective studies have described the extent and nature of sexual difficulties in this population, 4-6 and have also documented elevated problem rates relative to healthy controls. 3-4,7-8 The aims of this article are to review the state of knowledge about sexual dysfunction following HSCT, to examine issues related to sexual dysfunction, and to address strategies to treat these long term problems.HSCT is a procedure designed primarily for hematologic malignancies such as leukemia and lymphoma, although some solid tumors and non-malignant diseases such as aplastic anemia are also treated with this aggressive treatment method. Prior to the transplant, to prepare the body to receive stem cells, the conditioning regimens always include chemotherapy, usually supralethal doses of an alkylating agent such as cyclophosphamide or busulfan, and often including total body irradiation (TBI) at a dose of 1200 cGy or higher. This process lowers immune defenses so that stem cells from either marrow or peripheral blood, donated from oneself (autologous) or from another person (allogeneic) can be infused. If the transplant is allogeneic, survivors are at risk for chronic graft versus host disease (GVHD), where the donor immune cells identify the body as foreign and attack it. Chronic GVHD can manifest anywhere in the body and often involves the skin, liver, eyes, mouth, sinuses and gut. 2 For women, vaginal mucosal tissues are particularly susceptible. Chronic GVHD is managed with the use of immunosuppressants that often include high dose corticosteroids along with a calcineurin inhibitor such as cyclosporine or other newer agents that suppress immune recovery and bring a host of potential additional complications.Recent efforts to reduce the toxicities of HSCT have utilized very low dose chemotherapies and TBI in attempts to optimize a 'graft versus leukemia' effect. This increasingly widely used methodology for treating hematologic malignancies seems to spare gonadal function along with other organ systems, but risks for chronic GVHD remain.The population of HSCT survivors who receive high dose treatment is usually well under the age of 50, and most often relatively healthy until their diagnosis. Since treatment is so arduous and potentially toxic, major comorbidities are exclusions for eligibility for transplant. Thus