High-dose chemotherapy with autologous stem cell support is a new therapeutic modality for otherwise incurable malignancy. Peripheral blood stem cell(PBSC) is considered an excellent stem cell source alternative to bone marrow after myeloablative cytotoxic treatment. We treated 7 patients with malignant disease (5 lymphomas, one gastric carcinoma and one undifferentiated cancer) with high-dose chemotherapy followed by autologous peripheral stem cell support at Ajou University Hospital. All patients tolerated high-dose chemotherapy and reinfusion of PBSC well. Hematologic recovery was rapid and sustained. The response to high-dose chemotherapy was significantly improved as compared with that to prior conventional chemotherapy and /or radiotherapy, to which they had become refractory. We confirm the feasibility and value of collection and reinfusion of PBSC in conjunction with the high-dose chemotherapy.