Inhibitors of factor VIII or FIX in haemophilic patients are a common and serious complication associated with an increased risk of life-threatening bleeding during elective surgery. Substitution therapy fails to be effective, therefore an alternative treatment is needed. We have performed six major elective orthopaedic interventions in four patients with haemophilia A and inhibitors. A preoperative immunadsorbant therapy with Therasorb to eliminate inhibitors was successful in four cases, but during FVIII substitution inhibitors increased on day 4 to day 6 after surgery, leading to decreasing FVIII levels. Therefore, therapy was changed to recombinant FVIIa (rFVIIa; NovoSeven). Two interventions had to be covered with sole rFVIIa therapy as immunadsorbant therapy failed to be effective in one case and the need for acute intervention did not allow pretreatment in the other. We did not see increased bleeding during or after surgery when compared to our experience with non-inhibitor haemophilic patients. In conclusion, a preoperative decrease of inhibitors from immunadsorbant therapy, perioperative substitution of FVIII and changing treatment to rFVIIa when inhibitors are increased, is a safe and economic therapy for guaranteeing haemostasis in major elective orthopaedic surgery. On the contrary, sole therapy with rFVIIa allows immediate surgical intervention without a long hospital stay prior to surgery and a need for laboratory monitoring of inhibitor titres and FVIII levels. Our findings support data previously published.