We presented here a case with ALL transplanted with autologous marrow cells cryopreserved after heat treatment. Bone marrow cells from a 17-year-old female patient in first complete remission were cryopreserved after treatment with heat (42 degrees C, 60 min) and interferon-alpha. Three and a half years later, at her 4th remission, she was treated with busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) followed by autologous marrow infusion. The hemopoietic recovery after marrow infusion was prompt except in thrombopoietic lineage. She was doing well without limitation until leukemic relapse after 6 months. From this experience, marrow cells treated with heat and cryopreservation still include multipotent hemopoietic stem cells.