OBJECTIVES: This study aims to demonstrate the economic impact of using NovoSeven compared to Feiba for the initial treatment of mild to moderate bleeding episodes in patients with haemophilia A with inhibitors. METHODS: A budget impact model was developed based on a previous economic evaluation  to calculate the annual budget impact and the treatment cost per episode according to the different treatment strategies. The model presents the costs of the strategies to treat a mild to moderate bleeding episode with up to three lines of treatment, in which the impact parameters are the weight of the patient, the dose, the efficacy and the costs of medication and administration. Three treatment strategies were used: strategy 1: NovoSeven - NovoSeven - NovoSeven, strategy 2: Feiba - NovoSeven - NovoSeven  and strategy 3: Feiba - Feiba - NovoSeven. Costs per episode and annual costs were calculated based on local input data on costs and resources and the perspective used was of the Spanish National Health Service (NHS). RESULTS: Total costs per patient for one bleeding episode were €10,253, €11,852 and €12,042 for strategies 1, 2 and 3, respectively. Lower total costs per patient with NovoSeven are due to a reduced need for further treatment and associated hospitalisation. Only using NovoSeven saves €23,985 compared to strategy 2 and €26,842 compared to strategy 3 annually. CONCLUSIONS: The use of NovoSeven in all three lines of treatment in patients with in haemophilia A compared to using Feiba in the first line of treatment and in the first and second line of treatment saves €1,599 and €1,789 respectively per bleeding episode. This is mainly due to reduced need for further treatment and associated hospitalisation with NovoSeven. Annual cost savings using only NovoSeven are the consequence of lower drug cost and higher treatment efficacy with NovoSeven.