BACKGROUND Thrombolysis and angioplasty in the first hours after myocardial infarction minimize necrosis, leading to better early and late survival, but these therapies have limited effect in patients with three-vessel disease and cardiogenic shock. Emergency coronary surgery is an alternative treatment in some cases. OBJECTIVE To assess perioperative complications, mortality and long-term survival in patients undergoing coronary surgery within 24 h of myocardial infarction. METHODS We retrospectively studied 57 patients undergoing surgery within 24 h of the onset of symptoms of myocardial infarction between 1982 and 1998. Multiple vessel disease was present in 31 patients (54%), shock or cardiac arrest in 19 (33%) and coronary angiography complications in 7 (12%). The mean time between onset of symptoms and surgery was 6.32 h. At the beginning of surgery 32 patients (56%) were hemodynamically stable, 15 (26%) were in shock and 10 (17%) were in cardiac arrest. RESULTS The operative mortality was 0% for those who were hemodynamically stable at the start of surgery and 44% (11 of 25 patients) for those in shock or cardiac arrest. Shock or prior cardiac arrest were associated with higher rates of sternal infection and heart failure and longer hospital stays.Follow-up (mean 67 months) was possible for all remaining patients. The 5- and 10-year survival rates were 89 and 82%, respectively, for patients who were hemodynamically stable at the time of surgery. Five-year survival was 55%, however, for those who underwent surgery in shock or cardiac arrest. The overall rate of freedom from myocardial infarction, angioplasty or reoperation was over 95% at 5 years and over 85% at 10 years of follow-up. Age and shock or cardiac arrest were risk factors for a poor long-term outcome. CONCLUSIONS The early and long-term outcome of coronary surgery within 24 h of myocardial infarction is good for patients who are hemodynamically stable when surgery begins. Shock and cardiac arrest are important risk factors for complication and death. Coronary artery bypass grafting is a good treatment option in the first hours after myocardial infarction.