Recent developments in the field of magnetic resonance imaging (MRI) have opened up new opportunities in the investigation of disease. This review seeks to illustrate how some of these advances have made MRI a powerful tool with which to study the pathology and physiology of cerebral ischaemia. Emphasis will be placed on new techniques at the disposal of the MR investigator. These include techniques to monitor alterations in cerebral blood flow and volume; diffusion-weighted imaging to investigate the acute pathology of cerebral ischaemia; and techniques sensitive to alteration in tissue blood oxygenation levels that provide a wholly noninvasive means of assessing cerebral haemodynamics, including hyperaemia and CO2 reactivity. Particular reference to the ability of such techniques to identify ischaemic tissue prior to irreversible damage will be made, and the implication for pharmaceutical research and potential therapy will be discussed. A detailed technical description of nuclear MR theory is avoided, and we have concentrated on the application of MRI to interrogate the pathophysiology of cerebral ischaemia.