Clinical value and costs of G-CSF administration following autograft with mobilized peripheral blood progenitor cells (PBPC) were evaluated in two sequential groups of 20 patients each, treated for lymphoid neoplasms in the period February 1993 to January 1996. One group was given G-CSF (Filgrastim) (5 microg/kg/day), starting on day +1 until ANC was > 500/microl, the other received no G-CSF. All patients were conditioned with mitoxantrone 60 mg/m2 + L-PAM 180 mg/m2 and received large numbers of PBPC (median of 12 and 13 x 10(6) CD34+/kg, respectively). The median time to ANC > 500/microl was 10 days in the G-CSF group vs 14 days in controls (P < 0.0001). G-CSF was associated with a slightly faster platelet recovery (11 vs 13 days to plts > 20000/microl, P = 0.09). Median duration of fever (2.5 vs 5 days, P = 0.028), nonprophylactic antibiotics (8 vs 11 days, P = 0.019), and post-transplant hospitalization (13 vs 16 days, P = 0.0028) were also significantly reduced. The average cost per treatment in the G-CSF group amounted to about US$18241 as compared to US$21868 in the control group, implying a cost reduction of approximately 16%. Thus, G-CSF reduced morbidity with cost containment, supporting its use even if autograft is performed with large quantities of PBPC.