Introduction: The selection of endovascular thrombectomy (EVT) for acute ischemic stroke in the elderly remains challenging due to the underrepresentation of these patients in landmark randomized trials. The aim of this study was to assess the association between age and the pre-stroke modified Rankin scale score with functional outcomes after EVT in elderly patients aged ≥80 years. Methods: We prospectively collected data from consecutive elderly patients who underwent EVT of the anterior or posterior circulation at our institution between 2007 and 2022. Clinical and radiological parameters were analyzed using a fair outcome (mRS ≤3 or retained pre-stroke mRS score of 4) as the primary outcome. Results: In total, 307 elderly patients were included in the analysis. Fair functional outcomes were achieved in 162 (53%) patients. Eighty-four (27.4%) patients were deceased at 3-month follow-up and the mortality rate increased to 37.1% (114 deceased) at 1-year follow-up. The likelihood of achieving a fair functional outcome decreased by 8% for every 1-year age increase (OR 0.81, 95% CI 0.73–0.90). Lower National Institutes of Health Stroke Scale (OR 0.89, 95% CI 0.85–0.93, p < 0.001) and pre-stroke mRS (OR 0.67, 95% CI 0.53–0.84, p < 0.001) were associated with fair outcomes. Conclusions: EVT in elderly patients with stroke is beneficial in selected cases. Increasing age was associated with an increased risk of an mRS change to 4 or worse and death within 1 year. The pre-stroke mRS may aid clinicians in the selection of elderly patients for EVT.