We report serial MR findings in a 54-year-old woman with eosinophilic meningoencephalitis due to Toxocara canis infection, a parasitic disease contracted through exposure with soil contaminated by the eggs of the roundworm. MR imaging revealed several enhancing subcortical and white matter lesions in both lobes. Antihelminthic chemotherapy yielded marked improvement of the neurologic deficits and cerebral lesions. The specific MR findings-low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and contrast enhancement-and the clinical and epidemiologic features of CNS involvement are herein reviewed.