OBJECTIVE: Over the last 15 years pharmacoeconomics research has grown rapidly, but little is known about the actual use of economic information in health-care decision-making. We conducted semi-structured interviews with hospital pharmacists in a French region to determine the role of economic information in drug selection for hospital formularies. METHODS: We developed an interview schedule based on a literature review and three pilot interviews. We interviewed pharmacists in short stay hospitals with more than 100 beds. Thirteen public hospitals (PH) and six private clinics (PC) in the Rhone-Alpes region, in France, were randomly selected. Interviews were taped and the transcripts were coded independently by two researchers. We compared the six PC, financed on a fee-for-service basis, with the 13 PH, financed on a global budget basis, by multiple correspondence analysis. RESULTS: In all hospitals the drug's price and the quantity prescribed have an influence on formulary decision-making, especially for drugs used in the same indication with similar effectiveness and safety. The drug's price and the quantity prescribed seem to have more impact on PH than I-on PC. Information about costs avoided by the inclusion of a drug in the formulary might have an influence on decision-making: (1) time spent by nurses (5 PC and 9 PH); (2) medical devices (2 PC and 5 PH); (3) shorter hospital stays (2 PC and 4 PH). This information has little (6 PC and 10 PH) or very little (3 PH) impact and seems to have even less impact on PH than on PC. Moreover, published economic evaluations have very little impact on decision-making in all hospitals. CONCLUSION: In hospital formulary development, economic information is mostly used for cost-containment considerations, especially in PH, financed on a global budget basis. The current use of information related to economic evaluations and to costs avoided by the inclusion of a drug is limited, compared to its potential use.