Starting from May, 1991, 35 untreated myeloma patients entered a multicentric pilot study to evaluate the feasibility of a program of PBSC transplantation for previously untreated myeloma patients. The schedule was as follows: 2 cycles of VAD followed by CY, 7 g/mq+G-CSF (Granulokine, Roche) for 14 days, to increase and collect PBSC. The subsequent conditioning regimen was Melphalan+Busulfan followed by G-CSF. As maintenance R alpha-2 IFN was given, until relapse. The median follow-up is 14 months (4-22). On April 1993, 34 patients received at least 2 cycles of VAD, 27 were submitted to PBSC collection, 22 received conditioning regimen plus PBSC and 16 of them are in the maintenance treatment with IFN. Considering 28 patients for an intention to treat evaluation (35-7 in treatment), responding patients are 71% with 46% who achieved CR. White cells and platelets raised to > 1000/mmc and > 50,000/mmc after a median period of 10 and 13 days, from CY, and 11 and 14 days from transplant, respectively. Two patients relapsed, 2 others died while in PR because of CMV epatitis and candida pneumonia. The median number of CD34+ cells and CFU-GM was 24.75 x 10(6)/kg b.w. and 28.1 x 10(4)/kg b.w. respectively. In conclusion this treatment seems to be feasible and with low toxicity, but a longer follow-up is needed to evaluate the progression free survival of the high proportion of responding patients that we observed.