Localization of eloquent areas is of utmost importance in neurosurgical planning, especially in epilepsy surgery. Mass, destructive, or developmental lesions may distort brain anatomy. Functional MRI (fMRI) can localize eloquent areas despite these distortions and provide useful information for the planning of tailored resections. This paper deals with the major issues concerning the use of fMRI in epilepsy surgery, including its limitations. We present results derived from the clinical experience of the Epilepsy Surgery Center at Ribeira˜o Preto School of Medicine, where typical finger tapping and language fMRI paradigms were applied to 40 patients being considered for resective epilepsy surgery around eloquent cortex. Our results confirmed that although fMRI may not be used as a single tool for surgical planning, in conjunction with other methods it is useful in reducing the surgical time, it improves lesion resection, and prevents functional deficits. © 2004 American Institute of Physics