Background Patients with acute coronary syndrome (ACS) run increased risk of cardiac death or myocardial infarction after coronary artery bypass grafting (CABG). Long-term survival is similar in ACS patients and patients with stable angina pectoris. This study analyzed the cardiac rehospitalization rate up to 10 years after CABG for ACS and stable angina. Methods CABG was done in 200 patients, 100 with ACS and 100 with stable angina. Troponin-T levels were assayed and the severity of the unstable symptoms was classified according to Braunwald. Early outcome, long-term survival, and freedom from cardiac rehospitalization were analyzed. Results Three ACS patients died early and 12 died late. In the control group, there were no early and 19 late deaths. The cumulative long-term survival was 85% for the ACS patients and 81% for the stable patients ( p = 0.75). Postoperative myocardial infarction occurred in 5 unstable patients and 1 stable patient ( p = 0.01). At 3 years after the operation, freedom from cardiac rehospitalization was significantly higher in the stable patients (9 vs 27, p = 0.001). In the end of the follow-up, there were no differences in the rehospitalization rate. Conclusions Similar and excellent long-term survival was found in both ACS and stable patients long-term after CABG. In patients with ACS, variables such as elevated troponin-T and angina at rest herald an increased risk of perioperative myocardial infarction. Freedom from cardiac rehospitalization is significantly higher in stable patients compared with ACS patients during the first postoperative years, indicating recurrent ischemia.