Abstract The indications for coronary reconstruction have been extended to include those patients with the preinfarction syndrome who have failed to respond to medical therapy. Preinfarction syndrome is characterized by: (1) rapidly progressive angina; (2) exacerbation of previously stable angina; and (3) recurrent bouts of coronary insufficiency. During a three-year period 60 patients with this syndrome ranging in age between 30 and 72 years underwent urgent or emergency bypass procedures. Twenty showed electrocardiographic evidence of previous myocardial infarction. Single-vessel disease (> 75% obstruction) was demonstrated by coronary angiography in 18, double-vessel disease in 14, and triple-vessel involvement in 28. The operative technique is described. Eight sustained an early and 5 a late myocardial infarction with 1 and 3 deaths, respectively. A detailed analysis of these patients is presented including restudies and pathological findings. Of the 56 survivors, only 2 continue to have incapacitating angina. From this experience we conclude that the surgical management of a selected group of patients with the preinfarction syndrome is associated with a lower mortality and an improved functional result when compared with the natural history of the syndrome.