Atrial fibrillation is a major risk factor for stroke. Left atrial appendage closure (LAAC) has emerged as an alternative to anticoagulation for patients with high risk of bleeding. Diabetes mellitus (DM) is associated with adverse events after cardiac procedures. We sought to compare procedural and hospital outcomes in patients who underwent LAAC with and without DM. The Nationwide Inpatient Database was queried for patients with atrial fibrillation who underwent LAAC between January 1, 2016, and December 31, 2019. The primary outcome was all adverse events that included in-hospital death, acute myocardial infarction, cardiac arrest, stroke, pericardial effusion, pericardial tamponade, pericardiocentesis, pericardial window, and postprocedural hemorrhage requiring blood transfusion. Analysis included 62,220 patients who underwent LAAC from 2016 to 2019; 34.9% of patients had DM. There was a slight increase in the percentage of patients who underwent LAAC who had DM during the study period, from 29.92% to 34.93%. In unadjusted and adjusted analysis, there was no significant difference in all adverse events between patients with and without DM who underwent LAAC (9.18% vs 8.77%, respectively, adjusted p = 0.63), and no difference in length of stay. Patients with DM have higher risk of acute kidney injury (3.75 vs 1.96%, p <0.001). This nationwide retrospective study demonstrates that DM is not associated with an increase in adverse event rates in patients who underwent LAAC.