Background: Standard clinical practice permits the use of either single-chamber ventricular pacemakers (VVI) or dual-chamber pacemakers (DDD) for patients with atrioventricular (AV) block. However, it is unknown which type of pacing results in the better long-term outcome. This study was performed to evaluate the long-term benefit of dual-chamber pacing as compared with ventricular pacing for AV block. Methods: Four hundred sixty-four AV block patients (male 190, mean age 57 짹 19 years) without atrial fibrillation had been evaluated retrospectively. Pacing mode was DDD in 411 (88.6%) patents and VVI in 53 (11.4%) patients. Mean follow-up duration was 63 months. The primary end point was cardiac death. Secondary end points included the death from any cause, hospitalization for stroke or heart failure, and atrial fibrillation. Results: The cardiac death free survival rate did not differ significantly between DDD and VVI pacing. The rate of hospitalization for heart failure and atrial fibrillation was lower in DDD than VVI. In patients assigned to DDD pacing, the risk of atrial fibrillation (harzard ratio, 0.22; 95% confidence interval, 0.09 to 0.55, p=0.001) and the risk of heart failure (harzard ratio, 0.38; 95% confidence interval, 0.20 to 0.73, p=0.003) was lower. There was no significant difference in the incidence of stroke between two groups. DDD pacing had the lower risk of secondary event (harzard ration, 0.41; 95% confidence interval, 0.26 to 0.27, p=0.001) Conclusions: In patients with atrioventricular block, dual chamber pacing showed no benefitial effect in cardiac death compared with ventricular pacing. However, the rate of hospitalization for heart failure and atrial fibrillation was significantly lower in dual chamber pacing than ventricular pacing.