Purpose: To evaluate the clinical value of growth factors (GFs) with peripheral-blood stem cells (PBSC) collected following mobilization with GFs, we randomized patients to receive or not to receive GFs following transplant. Patients and Methods: Thirty-seven patients were apheresed after receiving the combination of granulocyte colony-stimulating factor (G-CSF) with granulocyte-macrophage colony-stimulating factor (GM-CSF) at doses of 10 μg/kg/d and 5 μg/kg/d, respectively, for 6 days before apheresis and during a median of 4 days of collections. One day after the infusion of autologous marrow and PBSC, patients were randomly assigned to receive no GFs or a combination of G-CSF (7.5 μg/kg/d) and GM-CSF (2.5 μg/kg/d), both as a 2- hour intravenous (IV) infusion twice per day until the neutrophil count was greater than 1,500/μL. Results: The median days to recovery to an absolute neutrophil count (ANC) of 100/μL (9 v 11.5, P = .0005), 500/μL (10 v 16, P = .0004), or 1,000/μL (12 v 21, P = .0008) was shortened with the use of GFs, post-PBSC infusion. In addition, the duration of hospitalization was shorter (19 v 21 days, P = .0112) in the arm receiving GFs post-PBSC infusion. There was no significant difference between the two study arms in the duration of fever, documented septic episodes, or RBC or platelet transfusion requirements. Conclusion: Despite faster neutrophil recovery and shortened duration of hospitalization with GFs administered after PBSC transplantation, the measured clinical variables of febrile days, septic episodes, and transfusion requirements were similar between the study arms. The use of GFs post-PBSC transfusion is associated with a modest clinical benefit.