Background: Little is known about the frequency of, risk factors predisposing to, and long-term impact of post-operative atrial fibrillation (AF) after lung transplantation. Methods: A prospectively collected registry of 167 consecutive patients who underwent single or bilateral lung transplantation at the University of Minnesota Medical Center from January 1st, 2004 to December 30th, 2008 was reviewed. Post-operative AF was confirmed by review of electrocardiograms by two cardiologists. Kaplan-Meier survival curves were constructed to determine the impact of new onset AF on long-term survival. Results: The mean age (±SD) of the population was 55 ± 11 years and 52% were male. A total of 48 patients (28%) developed AF in the postoperative period. Predictors of postoperative AF in multivariate analysis included: age (per decade) Odds Ratio (OR): 1.61, 95% confidence interval (CI) 1.10-2.34, p=0.01, postoperative thromboembolic disease OR: 9.73 (95% CI: 2.16-43.81, p<0.01, and postoperative pericarditis OR: 3.57, (95% CI: 1.38-9.22, p < 0.01). Of the 48 patients who developed post-operative AF, 41 were discharged in sinus rhythm (SR). Survival among patients who were discharged in AF was significantly lower when compared to patients discharged in SR (HR: 0.08; 0.01-0.43, p<0.05). Conclusions: Postoperative AF is common after lung transplant. Increased age, postoperative thromboembolic disease, and pericarditis are independent predictors of postoperative AF. Persistence of AF at the time of discharge is an identifier of decreased survival.