Fludarabine (FLUDA) based chemotherapy has shown promise in both initial and salvage treatment of low-grade non Hodgkin's lymphomas (LG-NHL). Recently, more aggressive therapies followed by autologous hemopoietic progenitor cell rescue, have also been successfully employed in these patients. However, this procedure, due to several factors including previous therapeutic regimens, is often limited by an inadequate collection of peripheral blood stem cell (PBSC). At present, very little data is available on the effect of FLUDA containing regimens in PBSC collection. We report our preliminary experience showing a possible correlation between FLUDA based chemotherapy regimens employed before mobilization and inability to collect an adequate number of blood derived hematopoietic progenitors for autologous PBSC transplantation in LG-NHL patients.