Autologous peripheral blood stem cell transplantation (PBSCT) is increasingly being utilised as an alternative to autologous bone marrow transplantation (ABMT) in the treatment of malignant diseases. We have performed a pharmacoeconomic study using cost-minimisation analysis to evaluate the two techniques in a population of multiple myeloma patients undergoing PBSCT (n = 37) or ABMT (n = 14). In the PBSCT group, the time to > 0.5 x 10(9)/l neutrophils was significantly shorter (16 vs 22 days; P = 0.0019) as was the time to > 50 x 10(9)/l platelets (19 vs 27 days; P = 0.0019). The faster haematopoietic recovery resulted in a reduced period of intravenous antibiotic therapy (12 vs 19 days; P < 0.0001), reduced requirements for platelet transfusions (12 vs 31.5 units; P = 0.0005), and ultimately, a significant reduction in duration of hospitalisation (19 vs 27.5 days; P < 0.0001). These clinical benefits translated into economic benefits such that the total cost in the PBSCT group was 27.5% less than in the ABMT group (< Pounds 7995 vs < Pounds 11026; P = 0.0001). We conclude that the use of PBSCT as an alternative to ABMT in patients with multiple myeloma is associated with demonstrable economic advantages in addition to clinical benefits.