INTRODUCTION: Cardioembolic and atherosclerotic occlusions are two leading causes of acute ischemic stroke with large artery occlusion. Cardioembolic cause is more frequent in strokes due to large vessel occlusion among strokes of all types. In this study, we aimed to analyze and determine the rate of cardioembolic cause in patients with LVO treated with mechanical thrombectomy. PATIENTS AND METHODS: This study is a retrospective analysis of 1,169 patients with LVO that were treated with mechanical thrombectomy in 2019. Both anterior and posterior circulation occlusions eligible for thrombectomy were included. RESULTS: Among the 1,169 patients who performed mechanical thrombectomy, there were 52.6 % males with a mean age of 63.2 ± 12.9 years and 47.4% females with a mean age of 67.4 ± 13.3 years. The average NIHSS score was 15.3 ± 4.8. The successful revascularization (mTICI 2b-3) rate was 85.2%, the 90-day good functional outcome rate (mRS 0-2) was 39.8% and mortality (mRS 6) rate was 22.9%. Most common causes of ischemic stroke were cardioembolism in 532/1,169 (45.5%), followed by 461/1,169 (39.5%) undetermined etiologies and others, 175/1,169 (15%) large vessel disease. Atrial fibrillation is found to be the most common cause of cardioembolic stroke with 76.3% incidence. We identified 11 (0.9%) acute stroke patients treated with MT who had recurrent LVO and received repeated MT. A cardioembolic cause was found to cause the recurrent LVO in 7 (63.6%) patients. CONCLUSIONS: In this retrospective study, cardioembolic source seems to constitute majority of causes in acute ischemic strokes due to large vessel occlusions. Further exploration is needed especially in cryptogenic strokes to reveal possible cardioembolic source of emboli.