OBJECTIVES: To assess the costs and cost-effectiveness of voriconazole in comparison to conventional amphotericin B for the treatment of invasive aspergillosis in Germany. METHODS: The cost-effectiveness of voriconazole in comparison to conventional amphotericin B was evaluated with a life-time Markov model, focusing on the long-term survival of patients treated for invasive aspergillosis. Long term survival was extrapolated from survival after 12 weeks of treatment, obtained from a large randomized aspergillosis study (Herbrecht et al. NEJM, 2002). Information on medical resource consumption, treatment pathways and switch rates were obtained from both this randomized study and an expert committee. Probabilistic analysis was used to evaluate the cost-effectiveness of voriconazole compared to amphotericin B, and was expressed by the incremental costs per life weeks gained. The evaluation was performed from an insurance perspective (both inpatient and outpatient costs) and hospital perspective (direct costs, inpatient). RESULTS: The mean survival of patients treated with voriconazole was 174.4 life weeks (95%CI 159.4; 191.3), compared to 119.4 life weeks (95%CI 106.4; 132.3) for amphotericin B. With voriconazole, the total mean costs for treating invasive aspergillosis per patient were 31,765€ (95%CI 24,094€; 39,383€) compared to 28,569€ for amphotericin B (95%CI €22,674; €36,860) from the insurance perspective. Total inpatient costs were approximately 85% of the total mean costs of treating aspergillosis infection. The corresponding incremental cost-effectiveness ratio was 18€ per life week gained, resulting in a >99% probability of being cost-effective for a willingness-to-pay threshold of 20,000€ per life year gained. CONCLUSIONS: In the treatment of invasive aspergillosis, voriconazole is cost-effective in comparison to amphotericin B. Inpatient costs had been represented within the current German reimbursement system (per diem charges), but are higher than those currently reimbursed within the newly introduced German DRG system.