Silicone balloons have recently been engineered for endovascular treatment of direct carotid cavernous fistulas. Complete closure of the fistula and preservation of the parent vessel are usually possible. Successful embolization of dural arteriovenous malformations is possible using either an arterial or venous approach. In cerebral arteriovenous malformations, new catheters developed include the Tracker catheter (Target Terapeutics, San Jose, CA). New substances are being investigated for use in embolization. Advances in physiologic monitoring include pressure monitoring with microcatheters, and the usefulness of sodium amobarbital has been confirmed for this purpose. Preoperative embolization often facilitates surgical removal of cerebral arteriovenous malformations. For intracranial aneurysms, endovascular treatment is appropriate when surgery is contraindicated. Reported rates of success for occluding the aneurysm range from 77.4% to 91%, and mortality rates range from 1.7% to 17.9%. Alternatives may include the use of thrombogenic coils. MR imaging and angiography are useful in evaluating thrombus formation and structure. A new nondetachable silicone balloon catheter system has been used successfully for intraluminal angioplasty of vasospastic vessels.