Perioperative ischaemia and infarction after CABG are associated with increased morbidity and mortality. Objective: To study causes of perioperative ischaemia and infarction by acute re-angiography and to treat incomplete re-vascularization caused by graft failure or any other cause. Methods: Between 1990 and 1995, 2003 patients underwent an isolated CABG operation. Myocardial ischaemia was suspected if one or more of the following criteria were present: New changes in the ST-segment in the ECG; a CKMB value greater than 80 U/L; new Q-waves in the ECG; recurrent episodes of, or sustained ventricular tachyarrhythmia; ventricular fibrillation; haemodynamic deterioration and left ventricular failure. Acute coronary angiography was performed in stable patients, while haemodynamically severely compromised patients were rushed to the operating room. Results: A total of 71 (3.5%) patients of all CABGs with suspected graft failure were identified and included in the study. Patients were grouped according to whether they had an acute re-angiography (n = 59; group 1) or an immediate re-operation (n = 12; group 2) performed. In group 1, the acute re-angiography demonstrated graft failure/incomplete re-vascularization in 43 patients (73%). The angiographic findings were: Occluded vein graft(s) in 19 (32%); poor distal run-off to the grafted coronary artery in ten (17%); internal mammary artery stenosis in four (7%); internal mammary artery occlusion in three (5%); vein graft stenoses in three (5%); left mammary artery subclavian artery steal in two (3%); and the wrong coronary artery grafted in one (2%). Based on the angiography findings, 27 patients were re-operated and re-grafted. At the time of re-operation, 18 patients (67%) had evolving infarction documented by ECG or CKMB. Two patients (3%) experienced stroke in immediate relation to the re-angiography. The 30-day mortality was three (7%). In group 2, graft occlusions were found in 11 patients (92%). The 30-day mortality was six (50%). Conclusion: An acute re-angiography demonstrated graft failure or incomplete re-vascularization in the majority of patients with myocardial ischaemia early after CABG. Re-operation for re-re-vascularization was performed with low risk. Few patients with circulatory collapse could be saved by an immediate re-operation without preceding angiography.