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 pop-ulation-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 hospitalreferred 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 highrisk 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 pop-ulation-based cohort (Oxford Vascular Study; OXVASC, n = 190). 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; 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] unilateral weakness = 2, speech disturbance without weakness = 1, other = 0], and duration of symptoms in min [ 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 cohort (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% ) 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 (15%) with a score of 5, and 31.4% (16.0-46.8) in 35 (9%) with a score of 6. In the hospitalreferred 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. Further validations and refinements are needed, the ABCD score can be used in routine clinical practice to identify highrisk individuals who need emergency investigators ationand treatment.