Post-operative large vessel occlusion (LVO) stroke is one of the most severe complications associated with cardiac surgery. Mechanical thrombectomy (MT) is the first-line treatment for LVO stroke. In this paper, we present cases of patients who underwent MT guided by multimodal computed tomography (CT) to treat LVO stroke after cardiac surgery at our institution to clarify the impact of MT on patient outcomes. We analyzed the in-hospital stroke database from July 1, 2023, to June 30, 2024, to identify patients who had undergone MT to treat LVO stroke after cardiac surgery in our institution. Demographic data, stroke severity, type of operation, imaging features, and 90-day modified Rankin scale (mRS) scores were assessed. Of the 21 patients receiving endovascular therapy, we included nine (42.9%) who had undergone multimodal CT-guided MT after cardiac surgery. The operations varied and comprised four coronary artery bypass grafts, four surgical valve replacements, and one extended Morrow myectomy. The median time from post-surgery to the onset of stroke symptoms was 4 days (interquartile range [IQR]: 2.5 – 5 days), the median National Institutes of Health Stroke Scale score was 16 (IQR: 15 – 18), and the median time between the onset of symptoms and recanalization was 320 min (IQR: 270 – 465 min). One patient died of severe cerebral hemorrhage, while eight patients survived and were discharged to another hospital (n = 1), a rehabilitation facility (n = 3), or home (n = 4). The median 3‐month mRS was 2 (IQR: 0.5 – 3). In summary, multimodal CT-guided MT can improve the prognosis of patients with LVO stroke, although severe neurological deficits and mortality were observed in some patients. A larger sample size is required to clarify the effects of MT.