This report describes two Spanish cases of acute necrotizing encephalopathy of childhood, a rare disease first described in Japan by Mizuguchi and colleagues. Similar cases have been reported from Taiwan and other countries of the Far East. Two cases have been reported from the UK and one from the USA. The disease affects young children and is characterized by acute encephalopathy after a viral illness, with seizures and decreased levels of consciousness. The hallmark of the disease is diffuse and symmetrical CNS lesions of both thalami, internal capsules, upper brainstem tegmentum, and cerebral white matter. The aetiology is unknown but an infectious or parainfectious process seems likely. Because of the predominant involvement of the thalami, we propose the term 'infantile bilateral thalamic necrosis', a more specific term and one which distinguishes the entity from other basal ganglia diseases in childhood.