BACKGROUND: Extracranial internal carotid artery stenosis is a risk factor for perioperative stroke in patients undergoing coronary artery bypass surgery (CAB). Although selective and non-selective methods of preoperative carotid screening have been advocated, it remains unclear if this screening is clinically relevant. AIM: To test whether selective carotid screening is as effective as non-selective screening in detecting significant carotid disease. METHODS: The case records of patients consecutively undergoing CAB were reviewed. Patients were stratified retrospectively into high- or low-risk groups according to risk factors for significant carotid stenosis and perioperative stroke: peripheral vascular disease (PVD), carotid bruit, diabetes mellitus, age >70 years and/or history of cerebrovascular disease. Prevalence of carotid stenosis detected by ultrasonography, surgical management and perioperative stroke rates were determined in each group. RESULTS: Overall, 205 consecutive patients underwent preoperative carotid screening. The prevalence of significant carotid stenosis was 5.8%. Univariate analysis confirmed that PVD (P=0.005), carotid bruit (P=0.003) and diabetes mellitus (P=0.05) were significant risk factors for stenosis. Carotid stenosis was a risk factor for stroke (P=0.03). Prevalence of carotid stenosis was higher in the high-risk group (9.1%) than the low-risk group (1.2%) (P<0.05). All concomitant or staged carotid endarterectomies/CAB (5/205) and all patients who had perioperative strokes (5/205) were in the high-risk group (P=0.01). CONCLUSION: In our cohort, selective screening of patients aged >70 years, with carotid bruit, a history of cerebrovascular disease, diabetes mellitus or PVD would have reduced the screening load by 40%, with trivial impact on surgical management or neurological outcomes.