A reversible posterior leukoencephalopathy, associated with cortical blindness, has been reported in both adults and children treated with Cyclosporine. The present study reports neuropsychological findings in a 6-year-old male, who received an allogenic bone marrow transplant and Cyclosporine treatment. Although visual acuity and neuro-opthalmological findings were normal 6 days after the onset of cortical blindness, neuropsychological findings indicated residual deficits suggestive of achromatopsia, and impairments in visuospatial perception, Visual memory, resolution of figure-ground relationships, facial recognition, and visual cognitive functions requiring imagery. Thirty days after the onset of symptoms, neuropsychological findings continued to demonstrate abnormalities in the use of color to resolve form, and impaired performance on measures which required visual imagery to provide figural closure.