The development of atrial fibrillation (AF) in cardiac patients is multifactorial, including not well defined genetic factors. To determine if Asian ethnicity is associated with the development of AF in patients with coronary disease, a meta-analysis was conducted of patient-level data from 7 prospective randomized clinical trials that prospectively collected information on the development of AF: 3 trials in patients with ST-elevation myocardial infarction (Global Use of Strategies to Open Occluded Coronary Arteries [GUSTO] I, GUSTO III, and GUSTO V), 3 trials in patients with non-ST-elevation acute coronary syndromes (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy [PURSUIT], Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis-II [IMPACT II], and Platelet IIb/IIIa Antagonist for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network [PARAGON A]), and 1 trial in patients with both conditions (GUSTO IIb). A total of 94,785 patients were identified (93,050 white, 1,735 Asian). At baseline, Asian patients were younger; had lower body mass indexes; had a lower prevalence of female gender, previous angioplasty, and previous coronary artery bypass grafting; and had a greater prevalence of diabetes compared with white patients. The development of AF was lower in Asian than in white patients (4.7% vs 7.6%, p <0.001), while rates of ventricular tachycardia and fibrillation were similar in the 2 groups. In multivariate logistic regression analysis, Asian ethnicity was associated with significantly lower rates of AF (odds ratio 0.65, 95% confidence interval 0.50 to 0.84, p = 0.001) compared with white ethnicity. In conclusion, similar to previous studies showing a lower incidence of AF in non-Caucasian populations, Asians experiencing acute ischemic syndromes have a significantly lower frequency of AF compared with whites. Further study is needed to investigate the mechanisms and potential genetic underpinnings behind this association.