We studied 14 chronic toluene abusers with a comprehensive neuropsychological evaluation and cerebral magnetic resonance imaging (MRI). There were 10 men and 4 women, and the mean age was 29 years. Using a blinded global assessment of neuropsychological functioning, we found 3 patients to be normal, 3 in a borderline range, and 8 impaired. Independent analyses of white matter changes on MRI disclosed that the degree of white matter abnormality was strongly correlated (p less than 0.01) with neuropsychological impairment. Dementia in toluene abuse appears to be related to severity of cerebral white matter involvement.