INTRODUCTION New-onset arrhythmias are a common problem in cardiothoracic surgery. They are also common following major non-cardiac surgery. This review examines the available literature to establish the incidence and significance of new-onset arrhythmias following major non-cardiothoracic surgery.MATERIALS AND METHODS A literature search was performed using the Medline and Pubmed databases using the terms 'postoperative arrhythmia', 'peri-operative arrhythmia', 'atrial fibrillation/flutter', 'supraventricular arrhythmia/tachycardia', 'cardiac complications' and 'non-cardiothoracic surgery'. Articles were cross-referenced for additional relevant publications and reviewed for data regarding new-onset arrhythmias following major non-cardiothoracic surgery.RESULTS There was considerable heterogeneity in the literature regarding cardiac monitoring, types of arrhythmias considered and potential associations investigated, thus hindering interpretation. The available data suggest that new-onset arrhythmias affect about 7% of patients following major non-cardiothoracic surgery. These arrhythmias are often associated with other underlying complications.