Sydenham's chorea has not previously been associated with abnormal findings on CT scan, but there have been reports of abnormal MRI in affected patients. The authors describe a case of Sydenham's chorea in which striatal abnormalities were found on both CT and MRI. Repeat MRI when the patient's illness had resolved was virtually normal. This suggests that abnormal imaging is entirely compatible with a diagnosis of Sydenham's chorea in a patient with an appropriate clinical history. Resolution of such abnormalities on repeat scanning provides further support for the diagnosis.