Amifostine (Ethyol) is an analog of cysteamine that selectively protects normal tissues in multiple organ systems against the toxic effects of radiation and various cytotoxic drugs while preserving the antitumor effects of these therapies. Amifostine was evaluated in a multicenter, multinational phase III clinical trial that enrolled women with stage III/IV ovarian cancer. Its effects have also been studied using normal human bone marrow and human breast cancer cells, as well as leukemia cells. Additional clinical trials have shown that amifostine can protect normal tissues from the toxic effects of alkylating agents, organoplatinums, anthracyclines, taxanes, and radiation. Other laboratory and clinical investigations indicate a potential role for this cytoprotective agent in the treatment of the ineffective hematopoiesis characteristic of the myelodysplastic syndromes.