Mantle cell lymphoma (MCL) is currently regarded as one of the most incurable lymphomas, although reliable prognostic indicators are not yet to be defined. In a previous report, it was indicated that most of the patients with immunohistochemically cyclin D1(+)-MCL pursued the lethal clinical course within 7 years, not having achieved complete remission (CR). Recently, a high dose chemoradiotherapy was carried out, this was supported by peripheral blood stem cell transplantation (PBSCT) using the CD34(+)-selection method in a 48-year-old female patient with cyclin D1(+)-MCL. The tumor cells were detected in her peripheral blood despite four courses of combination chemotherapy using CHOP regimen. Soon after the pre-conditioning of total body irradiation (TBI) and high dose melphalan, she received the PBSCT of 1.8 x 10(6)/kg CD34+ cells and showed rapid hematological recovery without life-threatening complications. The patient achieved CR and was alive, without disease, 730 days after PBSCT. Thus, CD34+ selected PBSCT appears to provide further insight into the effective treatment and possible cure of this aggressive disease, i.e. cyclin D1(+)-MCL.