We studied high-dose chemotherapy with autologous bone marrow transplantation (ABMT) for 10 patients with malignant lymphoma or breast cancer refractory to conventional chemotherapy. Conditioning regimen was consisted of cyclophosphamide 60 mg/kg/day, thio-TEPA 6 mg/kg/day, Etoposide 500 or 600 mg/m2/day for 3 consecutive days. Of 9 patients with measurable lesions, there were 5 with complete responses (CR) and 4 with partial responses (PR). Severe bone marrow suppression, mucositis, and diarrhea were observed in all patients. Furthermore, biliary stasis, which was unpredictable side effect, was observed in most patients. So, mucositis and/or hepatotoxicity were thought to be the dose-limiting factors. But these were not life-threatening and clinically manageable. All patients were received recombinant human granulocyte colony stimulating factor (rhG-CSF) at a dose of 300 micrograms/m2/day and which was effective for shortening the duration of leukopenia. In vitro Colony Forming Unit-granulocyte macrophage assay (CFU-GM assay) showed a significant correlation between the ability of colony formation and the days to recovery of granulocytes.