The authors describe clinical and MRI features of a girl and two boys, aged 9, 17 and 19 years, respectively, with Marinesco-Sjögren syndrome. The clinical findings included the major features of the syndrome, including growth deficiency, ataxia, cataracts, hypogonadism (in two) and seizures (in two). Truncal hypotonia (in three), microcephaly (in two) and leg spasticity (in two) were also present. MRI showed a very small cerebellar vermis in all three patients, various supratentorial abnormalities, an apparently small anterior pituitary gland in two and the absence of a posterior pituitary gland in all three. The MRI features are similar to the few reported pathologic findings for persons with Marinesco-Sjögren syndrome. MRI may be helpful in the early diagnosis of the disorder.