Among 234 hemophiliacs, 14 patients (5.9%) with intracranial and 1 patient (0.4%) with intramedullary hemorrhage were observed and examined. The average age at the time of hemorrhage was 17 years in patients with severe hemophilia and 43 years in patients with moderate hemophilia. The patients with mild hemophilia and intracranial bleeding were 5 and 58 years old, respectively. Eight intracerebral, 3 subdural and 4 subarachnoid hemorrhages were encountered. In 7 cases bleeding was posttraumatic and in 5 it occurred spontaneously. In 2 patients hemorrhage followed a sudden increase of intracranial pressure. In 1 patient reliable data could not be obtained. Four of the 8 patients with intracerebral bleeding died; all survivors displayed some residual neurological abnormalities. All patients suffering from subarachnoid bleeding recovered completely. No serious complications were encountered after 3 lumbar punctures, 5 cerebral angiographies and after 1 myelography. Only in 1 case with an acquired inhibitor did a local hematoma develop at the site of puncture for the angiography. The same diagnostic procedures should be performed after substitution therapy with anti-hemophiliac plasma in a hemophiliac without inhibitor as in non-hemophiliacs if intracranial or intramedullar bleeding is suspected. In hemophiliacs with an anticoagulant, angiography or lumbar puncture should be performed only in exceptional cases.