BACKGROUND: It has been suggested that scores for risk stratification of TIA patients might not identify patients with carotid stenosis or atrial fibrillation (AF) and that this might undermine the usefulness of such scores. METHODS: In patients with TIA in the Oxford Vascular Study, we studied the associations between ABCD and ABCD2 scores, the presence of > or =50% ipsilateral carotid stenosis or AF, and the risk of stroke at 7 days. RESULTS: Among 285 TIA patients (from 559 referrals of possible TIA), 69 (24.2%) had either > or =50% carotid stenosis (n = 29) or AF (n = 42), or both (n = 2). Although the ABCD and ABCD2 scores were highly predictive of stroke at 7 days (p or =50% carotid stenosis or AF. However, the scores did predict the 7-day stroke risk in patients with these pathologies: ABCD score (trend-p = 0.05); ABCD2 (trend-p = 0.03). Five of the 6 patients with AF or symptomatic stenosis who had a stroke within 7 days of their TIA had an ABCD score of > or =5 and all 6 had an ABCD2 score of > or =4. CONCLUSIONS: The ABCD and ABCD2 risk scores appear to identify patients with > or =50% carotid stenosis or AF who are at high risk of stroke. However, these findings should be interpreted with caution due to the small number of outcomes among these subgroups, and further validations are necessary.