The ultimate goal of treatment for patients with inhibitory antibodies should be to permanently eradicate the inhibitor by immune tolerance induction therapy (ITI). However, ITI procedures fail in a substantial number of patients and in many countries ITI is not even offered owing to its high cost. How patients with inhibitors are managed in different European countries is evaluated with a special focus on the use of by-passing agents, i.e. recombinant FVIIa (rFVIIa) and activated prothrombin complex concentrates (aPCC), as well as the type of monitoring performed. Investigators from 22 large haemophilia centres participating within the network of the European Haemophilia Therapy Standardisation Board (EHTSB) were asked to complete a questionnaire. rFVIIa was routinely used in all centres for both children and adults at dosages ranging from 90 to 250 mug kg(-1) at an interval of 2-4 h. aPCC was used in 85% of the centres in adults and in 25% of the centres in children with haemophilia A at dosages of 50-100 IU kg(-1) every 6-12 h. The corresponding figures for children and adults with haemophilia B were 40% and 15% of the centres, respectively. Higher dosages of both agents were considered in the case of life-threatening bleeds. General recommendations were developed, based on the information provided by the survey. The results clearly indicate the need for well-designed comparative studies to optimize the use of by-passing agents.