Voriconazole (VOR) is a broad-spectrum triazole that has been shown to be superior to amphotericin B deoxylate (AMB) as initial therapy for invasive aspergillosis (IA) in terms of response, survival, and safety in the largest comparative trial of IA to date (Herbrecht et al. NEJM 2002, 347:408-15). No economic evaluation has been conducted to assess the cost-effectiveness of VOR in Taiwan. OBJECTIVE: To assess treatment costs and cost-effectiveness of VOR compared with AMB as initial therapy of invasive aspergillosis. METHOD: Cost-effectiveness of VOR compared with AMB for treatment of invasive aspergillosis in Taiwan was evaluated with a decision- analytic model developed from clinical trial data supplemented with local data. Clinical success, survival, hospital stay by treatment pathway, and need for second line therapies were obtained from the clinical trial. Unit costs of medications and resources of medical care were obtained from Taiwan's national reimbursement system database. Data were collected from local experts on use of concomitant therapy, monitoring, and second line therapies. Cost-effectiveness was expressed as incremental cost per successful case and incremental cost per life saved. RESULTS: The average cost of treating invasive aspergillosis primarily with VOR was 547,002 New Taiwan Dollars compared with 493,060 NTD with AMB. Hospitalization costs and the cost of antifungal therapies were the largest contributors to cost in both the treatments. The incremental costs per life saved for VOR vs. AMB was 254,444 NTD (7,951 USD) and the incremental cost per successfully treated patient was 418,155 NTD (13,067 USD), respectively. CONCLUSION: Although treating patients with invasive aspergillosis with voriconazole costs more than AMB, the incremental costs per successful case and life saved for VOR is reasonable. VOR is likely to be a cost-effective treatment for invasive aspergillosis in Taiwan.