Surgical planning in arteriovenous malformations depends on the angiographic features of the lesion and its relationship with neighboring functional brain areas. Topographic evaluation of the lesion can be made on conventional images but the relationship with the functional areas cannot be revealed. Functional magnetic resonance imaging (MRI) has begun to be used more frequently in mapping memory, visual, language and sensorimotor areas. In our study, functional areas in or around arteriovenous malformations were evaluated with functional MRI before surgical or endovascular therapy. © 2005 Elsevier Ireland Ltd. All rights reserved.