Coronary subclavian steal (CSS) syndrome is a rare complication of coronary artery bypass graft surgery (CABG) involving the left internal mammary artery (LIMA) graft to the left anterior descending (LAD) artery. It results from stenosis of the left subclavian artery proximal to the LIMA, which compromises myocardial blood flow. The incidence of CSS syndrome is between 0.1-3.4% in the United States.1 Most cases occur as a result of long-standing subclavian stenosis due to progres-sion of the stenosis following CABG. We report a case of CSS syndrome, which presented as a non-ST elevation myocardial infarction (NSTEMI).