We compared magnetic resonance imaging of the optic nerves and chiasm with computed tomography in four patients (a 17-year-old girl, a 14-year-old boy, a 13-year-old girl, and a 22-year-old woman) with biopsy-proven or suspected optic gliomas. Orbital abnormalities were effectively viewed by both techniques. Gliomatous and normal optic nerves had similar spin-echo magnetic resonance imaging characteristics. Magnetic resonance was superior to contrast-enhanced computed tomography for identification of the intracranial optic nerves, chiasm, and optic tracts, but computed tomography delineated orbital anatomic and spatial relationships better.