OBJECTIVES: A budget impact model (BIM) was developed to estimate the economic impact of intraconazole in prophylaxis of invasive fungal infections (IFI) in patients with neutropenia in Spain. METHODS: A BIM was developed using published data for disease prevalence, population growth, pharmaceutical ex-factory prices, health care resource consumption and market shares forecasting for Spain. This study was developed under the perspective of the healthcare system and time horizon considered was 5 years with an annual discount rate of 3%. According to a panel of clinical experts, drugs considered in this study were all different “azoles” currently used in prophylaxis in Spain regardless whether they have been authorized for this purpose or not. These are the following ones: itraconazole, posaconazole, fluconazole and voriconazole. This model estimated the cost of this disease for the Spanish health care system with and without the partial replacement (from 5% to 15%) of posaconazale by itraconazole. All costs were referred to year 2009. RESULTS: According to official statistic, target population with hematologic cancers in prophylaxis of IFI in Spain would be around 70,000 patients in the first year, arriving at 75,000 in the 5th year. Direct medical costs for the next 5 years were estimated at €1424 million before the replacement of posaconazole by itraconazole. Costs were estimated at €1423 million whether this replacement would take place. CONCLUSIONS: The replacement of posaconazale by itraconazole in a very low percentage (from 5% to 15%) would represent a savings of €830,000 for the Spanish health care system in the next 5 years.