Hematopoietic growth factors have shown clinical benefits in patients undergoing chemotherapy and stem cell transplantation, but few studies have been performed to assess whether the benefits are worth the costs. We reviewed 196 patients undergoing T-cell depleted related donor bone marrow transplantation (BMT) between 1990 and 1996 to assess the effect of growth factor use on time to engraftment and costs of hospitalization. Beginning in 1994, based on encouraging results in autologous transplantation, patients (n = 81) were treated with granulocyte colony-stimulating factor (G-CSF) starting at day +1 after marrow infusion until engraftment. Between January 1, 1990 and January 1, 1994, patients (n = 115) did not receive growth factor. CD6 depletion of donor marrow was the only form of prophylaxis against graft-versus-host disease (GVHD). Despite receiving a lower stem cell dose (P = .004), the group receiving G-CSF had a decreased time to engraftment (20 days v 12 days, P < .0001) and time from marrow infusion to discharge (23 days v 17 days, P < .0001). In multivariate modeling, the use of G-CSF was the most significant factor predicting time to engraftment and discharge. Incidence of grades II-IV GVHD, early mortality, percentage of patients who engrafted, and relapse rates did not differ between the groups. Inpatient charges during the first 50 days after marrow infusion (including readmissions) were available on 110 patients and were converted to costs using departmental ratios of costs of charges. Median costs were significantly lower in the group receiving G-CSF ($80,600 v $84,000, P = .0373). Thus, use of G-CSF in this setting allows earlier hospital discharge with lower costs.