Toluene, a colorless liquid found in glues, paints, and industrial products, is lipid soluble and rapidly absorbed by the lipid-rich central nervous system. Prolonged exposure through occupation or purposeful inhalation may lead to neurologic abnormalities. Two men presented with multifocal central nervous system defects and bilateral optic neuropathy of unclear etiology. After numerous diagnostic tests, including brain magnetic resonance imaging, lumbar puncture, hematologic studies, and in one patient a brain biopsy, chronic inhalation of toluene was found to be the cause. Timely diagnosis is important because patients may experience improvement in neurologic and ocular manifestations with cessation of exposure, whereas continued inhalant abuse or exposure can result in permanent loss of neurologic function. © 2011 Elsevier Inc. All rights reserved.