Surgical anastomosis between branches of the external and internal carotid arteries may be beneficial in selected cases of transient ischaemic attacks and reversible ischaemic neurological deficit. It is the responsibility of the radiologist, at the time of initial angiographic evaluation, to recognise patients who might benefit from this procedure. Postoperatively, angiography is valuable in assessing the surgical results. This report describes the investigations necessary for the adequate evaluation of these patients in both the pre- and post-operative state.