A major challenge in the treatment of haemophilia patients is the development of autoantibodies against factor VIII. These patients are at particular risk if spontaneous bleedings or traumata occur or if surgery is necessary. In case of an unsuccessful immune tolerance therapy with high i.v. doses of factor VIII, treatment with recombinant factor VIIa or activated prothrombin complex should be considered. This article summarises data of three patients with severe haemophila A due to an inversion of intron 22 in the FVIII gen. All three patients had autoantibodies against FVIII. The therapy of these patients with rFVIIIa was safe and effective. Furthermore a prophylactic therapy with rFVIIa (at an individual dose of 180-270 microg/kg body weight) reduced the number of spontaneous bleedings in joints and muscles as well as in other locations significantly. The reduced rate of spontaneous bleedings improved the mobility and the quality of life in the young patients studied.