SynopsisMajor clinical neurological features were seen in 13 of 25 consecutive patients with the haemolytic uraemic syndrome (HUS). Convulsions were present in 11 of these patients Hemiparesis, aphasia, coma, and decerebrate spasms were other manifestations and these were associated with a mortality of 90% compared with an overall mortality of 45%. Two case histories are given in which neurological involvement was the presenting and predominant clinical feature. Neuropathological examination showed hypoxic and/or ischaemic lesions and cerebral oedema as the most frequent changes, but did not reveal distinctive vascular lesions similar to those seen in the kidney. The diagnosis of HUS should be considered in severe acute and subacute encephalopathies of obscure origin in childhood.