The recent observation that mobilized peripheral blood progenitor cells (PBPCs) can be used as a source of hematopoietic support has had a major effect on the cost and morbidity associated with bone marrow transplantation in patients with breast cancer. The pharmacoeconomic impact of this new technology is especially evident when secondary costs are analyzed. We see a reduction in hospital stay, decreased use of resources such as platelet transfusions and antibiotics, and long-term quality life-years gained for those patients benefiting from this therapy. Experienced transplant centers have found that the direct cost of high-dose chemotherapy using filgrastim and PBPC support is reduced as much as 50% to the patient or their insurance company. Pharmacists will play a key role in optimizing the benefits of PBPC transplantation, particularly because this therapy is moving to the outpatient arena. This article will review the pharmacoeconomic impact of PBPC transplantation primarily in terms of secondary cost measures and quality of life and discuss the limited direct cost data available and the impact of this therapy on pharmacy practice.