Transplant studies in a variety of malignant diseases suggest that dose intensification with peripheral stem cell support can be safely applied to a wide range of patients. The clinical results are comparable to that after autologous bone marrow transplantation by achieving long lasting remissions, even in advanced disease. Clinical studies evaluating this therapeutic modality in leukemias, Hodgkin's-and non-Hodgkin's lymphoma, myeloma, and in chemotherapy-sensitive solid tumors are in progress. The clinical results compared to conventional chemotherapy are summarized in Table 1. Several approaches are targeted at improved elimination of malignant cells: 1) incorporation of new drugs into preparative conditioning regimens, 2) tandem or multiple cycles of high-dose chemotherapy followed by stem cell rescue, 3) post-transplant immunomodulation aimed at inducing an antitumor effect, and 4) purging techniques to eliminate contaminating tumor cells from the transplant. Improvements in stem cell technology and supportive care will decrease the mortality of the procedure and leed to a substancial cost reduction.