OBJECTIVE Conducting system defects are common in patients with aortic valve disease. Aortic valve replacement may result in further conduction abnormalities requiring permanent pacemaker implantation. The aim of our study was to identify the incidence and predictors for postoperative 30-day permanent pacemaker implantation in patients undergoing isolated aortic valve replacement, and the effect of an accurate surgical technique in order to prevent permanent pacemaker implantation. METHODS Data from 261 consecutive patients (mean age 69 +/- 12 years, 136 men) undergoing isolated aortic valve replacement from January 2004 to January 2008 were analyzed retrospectively. Indications for aortic valve replacement were aortic valve stenosis (n = 156), stenoinsufficiency (n = 63), regurgitation (n = 42). Aortic bicuspid valve was present in 25% of cases (n = 64), redo operation was the indication in 7% (n = 18). Preoperative conducting system disease, defined as first-degree atrioventricular block, left or right bundle-branch block or left anterior hemiblock, was present in 25.6% (n = 67) of patients. An accurate surgical technique for debridement of calcific material was performed. RESULTS In-hospital mortality was 0.8% (2 out of 261 patients). Postoperatively, 8 out of 261 patients (3%) required permanent pacemaker implantation, for second-degree (n = 1) or complete atrioventricular block (n = 7). Incidence of permanent pacemaker implantation was similar for patients either with or without preoperative conducting system disease (25 vs. 25.7%, P = NS). Independent predictors of permanent pacemaker implantation were greater preoperative end-systolic diameter (P = 0.026) and left ventricular septum hypertrophy (P = 0.041). CONCLUSIONS Need of permanent pacemaker implantation after aortic valve replacement seems to be related more to preoperative advanced aortic valve disease rather than pre-existing conducting system abnormalities. An accurate surgical technique for aortic valve replacement probably helps to prevent further impairment of conducting system function requiring early postoperative permanent pacemaker implantation.