Background: Recent reports have shown that CHADS₂ score can be applied to stroke risk in coronary artery disease (CAD) patients. This study evaluated the efficacy of CHADS₂, CHA₂DS₂-VASc and R₂CHADS₂ scores as prognostic tools for stroke subsequent to CAD. Methods and Results: We enrolled 159 consecutive patients with acute ischemic stroke who were (1) living independently before stroke; and (2) diagnosed with CAD before stroke. Comparisons were made between patients with poor and good 3-month functional outcome (modified Rankin scale ≥3 and <3, respectively) with regard to clinical characteristics and pre-stroke CHADS₂, CHA₂DS₂-VASc and R₂CHADS₂ scores. Multivariate analysis was used to assess the predictive value of each of the 3 scores for poor outcome. The patients with poor and good outcomes had significant differences in intracranial artery stenosis (31.4% vs. 14.9%; P=0.016), carotid artery stenosis (41.9% vs. 23.9%; P=0.019), atrial fibrillation (37.2% vs. 17.9%; P=0.008), NIHSS (11 vs. 5; P<0.001), CHADS₂ (3 vs. 2; P=0.004), CHA₂DS₂-VASc (5 vs. 4; P=0.003), and R₂CHADS₂ (3 vs. 3; P=0.005). Multivariate analysis showed that CHADS₂ >2 (OR, 1.65; 95% CI: 1.05–2.65; P=0.032), CHA₂DS₂-VASc >4 (OR, 1.60; 95% CI: 1.02–1.78; P=0.042), and R₂CHADS₂ >3 (OR, 1.57; 95% CI: 1.01–2.49; P=0.049) positively predicted poor outcome. Conclusions: CHADS₂, CHA₂DS₂-VASc and R₂CHADS₂ are useful in predicting functional status after stroke in CAD patients.  (Circ J 2014; 78: 1481–1485)