BACKGROUND Atrial fibrillation (AF) is defined as a rapid, irregular heart rate, which makes it impossible for the heart to pump the blood adequately in the arteries. In women, AF is associated with more severe symptoms and worse prognosis. Catheter ablation is often described as the cure of AF, compared with antiarrhythmic therapy, which is just controlling the AF. OBJECTIVE We sought to assess sex-related differences in complications after catheter ablation in elderly patients with atrial fibrillation METHODS A total of 995 patients (female (f): 455(45.7%), male (m): 540 (54,3%)) over 70 years receiving a cardiac ablation after atrial fibrillation from January 2007- January 2010 with a one year follow-up were gathered from the German Ablation Registry and were compared between male and female patients. RESULTS The median age for both sex is 73 years. 125 (27.5%) females and 122 (22.6%) males are older than 75 years. Elderly male patients had a higher incidence of cardiac comorbidities (f: 48.4%, m: 58.9%, P=<0.001). Other comorbidities had a higher frequency in elderly female patients, but these results were not significant. Nearly all patients (female: 98,5%, male: 98,1% P= 0.7) described palpitations occurring at minimum once a month. In female patients the CHA2DS2- VASc-Score is significantly higher than in men (P=<0.001) but overall, the procedure-time was lower in the female cohort (1800 sec. female, 2340 sec. male, P=<0,025). There was no significant difference in the success rate (female 95.4%, male 96.7% P= 0.30). Overall non-fatal complications occurred more often in the female cohort then in the male cohort, and mainly driven by major bleeding events (f: 2,4%, m: 0,7% P=<0.037). At the follow up most patients in both gender groups notified either a reduction of symptoms or no symptoms at all (f: 86%, m:79,7% P=0.014). There was no significant difference between female and male patients who reported an increase in worsening of the symptoms (f: 5%, m: 2,6% P=0.063). Women also had a significantly higher incidence rate in documented AF recurrency than men (f:46,2%, m:39,5%, P=0.038) and had more severe physical limitations, classified with NYHA (NYHA II+ f:58.6%, m: 40.6%, P= 0.001). Moderate complications rates and major complication were presented in the same manner in elderly female and elderly male patients. Most patients received beta blocker as a therapy, but women received oral medication for rhythm and rate control more frequently. CONCLUSION Catheter ablation of AF in elderly patients was associated with a connection between gender differences and the complications rates. This study clarified that there is an increased recurrency of AF in elderly women than in elderly men in the one-year follow up.