In the three year period of 1982 to 1985, 152 patients with intracranial vascular malformations were referred to the Bicetre Hospital in Paris, France and the Toronto Western Hospital in Canada. Sixty-six patients with cerebral vascular malformations and 48 patients with dural vascular malformations underwent endovascular treatment. In 8 patients surgery was performed in combination with the embolization procedure. Detailed analysis of the angio-architecture of the vascular malformation reveals certain characteristics which may be of value in predicting the clinical outcome. Comprehensive data analysis and long term follow-up is necessary to assess the role of embolization in the treatment of intracranial vascular malformations.