While the efficacy and safety of coronary artery bypass grafting (CABG) has been established in several clinical trials, little is known about its outcomes in Native Americans. MEASUREMENTS AND MAIN RESULTS: We assessed clinical outcomes associated with CABG in 155 Native Americans using a national database of 18,061 patients from 25 nongovernmental, not-for-profit U.S. health care facilities. Patients were classified into five groups: 1) Native American, 2) white, 3) African American, 4) Hispanic, and 5) Asian. We evaluated for ethnic differences in in-hospital mortality and length of stay, and after adjusting for age, gender, surgical priority, case-mix severity, insurance status, and facility characteristics (volume, location, and teaching status). Overall, we found the adjusted risk for in-hospital death to be higher in Native Americans when compared to whites (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.5 to 9.8), African Americans (OR, 3.4; 95% CI, 1.1 to 9.9), Hispanics (OR, 7.1; 95% CI, 2.5 to 20.3), and Asians (OR, 2.8; 95% CI, 1.1 to 7.0). No significant differences were found in length of stay after adjustment across ethnic groups. CONCLUSIONS: The risk of in-hospital death following CABG may be higher in Native Americans than in other ethnic groups. Given the small number of Native Americans in the database ( n = 155), however, further research will be needed to confirm these findings.