Background: Effective early management of patients with transient ischaemic attacks(TIA) is undermined by an inability to predict who is at highest early risk of stroke. Methods: We derived a score for 7-day risk of stroke in a population-based cohort of patients(n=209) with a probable or definite TIA(Oxfordshire Community Stroke Project; OCSP), and validated the score in a similar population-based cohort(Oxford Vascular Study; OXVASC, n=190). We assessed likely clinical usefulness to frontline health services by using the score to stratify all patients with suspected TIA referred to OXVASC(n=378, outcome: 7-day risk of stroke) and to a hospital-based weekly TIA clinic(n=210; outcome: risk of stroke before appointment). Results: A six-point score derived in the OCSP(age[≥60 years=1], blood pressure[systolic >140 mm Hg and/or diastolic ≥90 mm Hg=1], clinical features[unilateral weakness=2, speech disturbance without weakness=1, other=0], and duration of symptoms in min[≥60=2, 10-59=1,< 10=0]; ABCD) was highly predictive of 7-day risk of stroke in OXVASC patients with probable or definite TIA(p< 0.0001), in the OXVASC population-based cohort of all referrals with suspected TIA(p< 0.0001), and in the hospital-based weekly TIA clinic-referred cohort(p=0.006). In the OXVASC suspected TIA cohort, 19 of 20(95%) strokes occurred in 101(27%) patients with a score of 5 or greater: 7-day risk was 0.4%(95%CI 0-1.1) in 274(73%) patients with a score less than 5, 12.1%(4.2-20.0) in 66(18%) with a score of 5, and 31.4%(16.0-46.8) in 35(9%) with a score of 6. In the hospital-referred clinic cohort, 14(7.5%) patients had a stroke before their scheduled appointment, all with a score of 4 or greater. Conclusions: Risk of stroke during the 7 days after TIA seems to be highly predictable. Although further validations and refinements are needed, the ABCD score can be used in routine clinical practice to identify high-risk individuals who need emergency investigation and treatment. Background: Effective early management of patients with transient ischaemic attacks (TIA) is undermined by an inability to predict who is at highest early risk of stroke. Methods: We derived a score for 7-day risk of stroke in a population-based cohort of Patients (n = 209) with a probable or definite TIA (Oxfordshire Community Stroke Project; OCSP), and validated the score in a similar population-based cohort (Oxford Vascular Study; OXVASC, n = 190) frontline health services by using the score to stratify all patients with suspected TIA referred to OXVASC (n = 378, outcome: 7-day risk of stroke) and to a hospital-based weekly TIA clinic (n = 210; outcome: risk of stroke Results: A six-point score derived in the OCSP (age [≥60 years = 1], blood pressure [systolic> 140 mm Hg and / or diastolic ≥90 mm Hg = 1], clinical features [unilateral weakness = 2, speech disturbance without weakness = 1, other = 0], and duration of symptoms in min [≧ 60 = 2, 10-5 Was highly predictive of 7-day risk of stroke in OXVASC patients with probable or definite TIA (p <0.0001), in the OXVASC population-based cohort of all referrals with suspected TIA ( In the OXVASC suspected TIA cohort, 19 of 20 (95%) strokes occurred in 101 (27%) patients with a score of p <0.0001), and in the hospital-based weekly TIA clinic- referred cohort 5 or greater: 7-day risk was 0.4% (95% CI 0-1.1) in 274 (73%) patients with a score less than 5, 12.1% (4.2-20.0) in 66 5 and 31.4% (16.0-46.8) in 35 (9%) with a score of 6. In the hospital-referred clinic cohort, 14 (7.5%) patients had a stroke before their scheduled appointment, all with a score of 4 or greater. Conclusions: Risk of stroke during the 7 days after TIA seems to be highly predictable. ABCD score can be used in routine clinical practice to identify high-risk individuals who need emergency investigation and treatment .