We report here three cases of peripheral T-cell lymphoma unspecified (PTCL-US), which presented with bone marrow infiltration and hepatosplenomegaly and were successfully treated with high-dose chemotherapy (HDCT) and autologous peripheral blood stem cell transplantation (auto-PBSCT). The patients were all characterized by cytokine-induced symptoms such as fever, anasarca, cytopenia, poor general condition, and disseminated intravascular coagulation syndrome. Laboratory data showed extremely high levels of soluble interleukin-2 receptor, beta(2)-microglobulin, and ferritin. All three patients were negative for anti-adult T-cell leukemia antibody. In one patient, hemophagocytosis was revealed by a histological examination of the bone marrow. The International Prognostic Index was high for all three patients, and they all achieved complete remission after the intensive chemotherapy for remission induction. During complete remission, they were treated with HDCT [modified interleukin-converting enzyme regimen] followed by auto-PBSCT. The recovery of hematopoiesis after auto-PBSCT was prompt and sustained engraftment was obtained. No serious adverse effects other than myelosuppression were noted. One patient died due to cerebrovascular disease without relapse 18 months after auto-PBSCT. The other two patients are still alive and have not suffered from relapse. Our observations suggest that auto-PBSCT following HDCT may be an effective and safe therapeutic modality for high-risk PTCL-US patients characterized by hepatosplenomegaly and cytokine-induced syndrome.