Up to 50% of patients undergoing mitral valve surgery have concomitant atrial fibrillation. An epicardial approach may offer the benefit of reducing the aortic cross-clamping time and avoiding an undue left atriotomy. During the last year we have been developing a simple technique to reproduce epicardially the same lesion pattern we had previously achieved endocardially. Two patients with chronic atrial fibrillation received atrial ablation using a microwave energy probe (Flex-10, AFx Inc., Fremont, CA, USA) immediately before undergoing a concomitant cardiac procedure. The procedure is relatively quick to perform and with appropriate care can be conducted with a low risk of perioperative adverse events.