Summary:The therapeutic options for brain-stem vascular malformations have expanded, and postoperative morbidity has declined, with renewed interest in skull base surgery, surgical lasers, electrophysiologic stimulation of cranial nerve nuclei, intraoperative ultrasound, and intraoperative angiography. This article reviews experience (1984–1993) in evaluating the long-term results of 63 patients with brain-stem vascular malformations; 27 patients were treated surgically, and 36 were observed. There were 45 cavernous angiomas, 13 arteriovenous malformations (AVMs), five capillary telangiectasias, and nine associated venous angiomas. Forty-one (65%) of 63 were located in the pons. Hemorrhage was the initial presentation in 54 (86%) patients; 23 (42.5%) suffered repeat hemorrhages. Surgery was performed when the malformation was near the brain-stem surface, when the neurologic status deteriorated, and in cases of repeat hemorrhage. Resection of venous angiomas was avoided. Of 27 surgical patients, 15 (56%) had transient worsening of their neurologic status and five (18.5%) suffered permanent neurologic deficits that included truncal ataxia, internuclear ophthalmoplegia, abducens palsy, paralysis of upward gaze, and nuclear facial weakness. Two patients (13.5%) suffered a recurrent hemorrhage from residual malformation. There was no mortality. Neurologic improvement occurred in 23 (85%) surgical patients, and 24 (89%) returned to independent living with functional neurologic capacity. Results improved with surgical experience and technical advances, leading the authors to conclude that surgical treatment is the best option for brain-stem vascular malformations. Observation is reserved for deep-seated and asymptomatic cavernous angiomas; stereotactic radiosurgery is preferred for intraparenchymal AVMs and unruptured AVMs of the tectum and ventral brain stem.