OBJECTIVE: To explore gender differences in real-world outcomes after catheter ablation of atrial fibrillation (AF). BACKGROUND: Compared to men, women with AF have greater thromboembolic risk and tend to be more symptomatic. Catheter ablation is generally more effective than antiarrhythmic drug therapy alone. However, there is limited data on the influence of gender on AF ablation outcomes. METHODS: We analyzed medical claims of 45 million United States patients enrolled in a variety of employee-sponsored and fee-for-service plans. We identified patients who underwent an AF ablation from 2007 to 2011 and evaluated 30-day safety and one-year effectiveness outcomes. RESULTS: Of the 21,091 patients who underwent an AF ablation, 7,460 (29%) were female. Women, compared to men, were older (62±11 vs. 58±11 years), had higher CHADS2 (1.2±1.1 vs. 1.0±1.0), higher CHA2DS2-VASc (2.9±1.5 vs. 1.6±1.4), and higher Charlson comorbidity index scores (1.2±1.3 vs. 1.0±1.2)(p<0.001 for all). Following ablation, women had higher risk of 30-day complications of hemorrhage (2.7 vs. 2.0%,p<0.001) and tamponade (3.8 vs. 2.9%,p<0.001). In multivariable analyses, women were more likely to have a re-hospitalization for AF (adjusted HR 1.12,p=0.009), but less likely to have repeat AF ablation (adjusted HR 0.92,p=0.04) or cardioversion (adjusted HR 0.75,p<0.001). CONCLUSION: Women have increased hospitalization rates after AF ablation and are more likely to have a procedural complication. Despite the higher rate of hospital admissions for AF after ablation, women were less likely to undergo repeat ablation or cardioversion. These data call for greater examination of barriers and facilitators to sustain rhythm control strategies in women.