THE RESULTS IN the surgical management of 26 patients with arteriovenous malformations intimately related to the trigone of the lateral ventricle are presented. Three operative approaches were used in the series, including a transtemporal route through the inferior or middle temporal gyrus (15 patients), an interhemispheric approach (8 patients), and a transcortical parieto-occipital approach (3 patients). The surgical approach was chosen on the basis of the relationship of the arteriovenous malformation to the trigone, the presence and location of associated hematoma, and preoperative neurological deficits. This report emphasizes the use of surgical adjuncts that are instrumental in the management of these challenging lesions, including magnetic resonance imaging for precise localization and operative planning, preoperative embolization to obliterate deep arterial supply, and intraoperative ultrasound and angiography to aid in localization and to document complete excision of the arteriovenous malformation before closure. The results of the management of these 26 patients are as follows: 21 had no or minor neurological deficits and were able to resume premorbid activities; 2 had a fair result, being independent but unable to resume their premorbid occupation; 2 had a poor result and were dependent as the result of an incapacitating neurological deficit; and 1 died.