Coronary-subclavian steal syndrome entails the reversal of blood flow in a previously constructed internal mammary artery coronary conduit, which produces myocardial ischemia. The most frequent cause of the syndrome is atherosclerotic disease in the ipsilateral, proximal subclavian artery. Although coronary-subclavian steal was initially reported to be rare, the increasing documentation of this phenomenon and its potentially catastrophic consequences in recent series suggests that the incidence of the problem has been underreported and that its clinical impact has been underestimated. We review the causes and background of coronary-subclavian steal; methods of preventing, diagnosing, and treating it; and the potential influence of various treatment regimens on long-term survival and the likelihood of late adverse events in patients with coronary-subclavian steal syndrome.