In countries with a good standard of health care, intracranial haemorrhage (ICH) during the neonatal period affects 3.5-4.0% of all haemophilia boys, which is considerably (40-80 times) higher than expected in the normal population. ICHs are also frequent after the neonatal period, affecting 3-10% of the haemophilia population who are mainly treated on demand. The risk is higher in inhibitor patients. Spontaneous haemorrhage is reported more frequently than trauma-induced haemorrhage in most studies. The prevalence of ICH in patients treated with a prophylactic regimen is not known. Although more frequent in younger patients, a substantial proportion of ICH occur in adults, suggesting that general risk factors because of age, such as hypertension, are increasingly important as the haemophiliac gets older. Some studies have reported a substantial proportion of ICH affecting patients with milder forms of haemophilia. The risk of ICH has to be considered when discussing treatment strategies for haemophilia patients.