Abstract Aims Left atrial appendage occlusion (LAAO) with WATCHMAN device is being used for patients with atrial fibrillation (AFB) and, as an off-label use, atrial flutter (AFL) who can't comply with long-term anticoagulation. We aim to study the differences in outcomes between sexes in patients undergoing Watchman device implantation. Methodology The National Inpatient Sample was queried between 2016 and 2019 using ICD-10 clinical modification codes I48x for AFB and AFL. Patients who underwent LAAO were identified using the procedural code 02L73DK. Comorbidities and complications were identified using ICD procedure and diagnosis codes. Differences in primary outcomes were analyzed using multivariable regression and propensity score matching. Results 38 105 admissions were identified, of which 16 795 (44%) were females (76 ± 7.6 years) and 21 310 (56%) were males (75 ± 8 years). Females were more likely to have cardiac (frequencies: 5.8% vs 3.75%, aOR: 1.5 [1.35-1.68], p1 day inpatient (1.79 [1.67-1.93], P < 0.01) and be discharged to a facility (1.54 [1.33-1.80], P < 0.01). Conclusion Females are more likely to develop cardiac, renal, bleeding, pulmonary and TEE-related complications following LAAO procedure, while concurrently showing higher mortality, length of stay and discharge to facilities.