Aicardi-Goutières syndrome (Mendelian inheritance in man Catalog No *225750) is an autosomal recessive encephalopathy which causes developmental arrest, intracerebral calcification, and white matter disease in the presence of chronic cerebrospinal fluid lymphocytosis, and a raised level of cerebrospinal fluid interferon-alpha (IFN-alpha). Diagnosis requires the presence of progressive encephalopathy with onset shortly after birth, and characteristic clinical neurological and neuroimaging signs together with chronic CSF lymphocytosis. The syndrome has superficial resemblance to the neurological sequelae of congenital infection, thus a rigorous search for microbiological and serological evidence of embryopathic infections should be carried out in each case.