Sneddon syndrome is characterized by the association of livedo reticularis and cerebrovascular ischemic events. Clinical and MRI aspects are described in 26 patients with Sneddon syndrome. MRI features were classified in 6 groups according to the aspect and topography of the lesions. No correlation was found between the presence of vascular risk factors, valvulopathy or antiphospholipid antibodies and the presence of dementia or MRI lesions. There was a significant correlation between MRI extension of the lesions and clinical disability. Clinical course and MRI findings are presented according to the treatment.