A questionnaire was sent to all 155 consultant physicians and geriatricians in the Yorkshire region who routinely admit patients with acute stroke in order to ascertain: (a) current opinion regarding the prescription of aspirin to patients with various manifestations of cerebrovascular disease, in particular the timing of initial treatment; and (b) the perceived role of computed tomography (CT) scans in relation to such therapy. The response rate was 81% (126/155). Aspirin was reported to be prescribed routinely by 75% (95/126) of physicians for patients with completed stroke. Amongst those prescribing aspirin, treatment was reported to be initiated routinely within 48 hours of the onset of symptoms by 63% (60/95). Only 10% (6/60) of these physicians reported that they would withhold aspirin therapy until the result of a cranial CT scan was known, although 43% (26/60) thought a CT scan was desirable. Our survey, which for logistical reasons is one of opinion rather than actual practice, suggests that aspirin is probably being prescribed acutely (less than 48 hours) after stroke to a significant number of patients and often without a pretreatment CT scan. As with patients who have had a CT scan, the balance of risks and benefits of this practice are unknown. We conclude that it would be ethical for acute treatment trials to allow randomization to aspirin without prior CT scan.