Objective To analyze the impact of frailty， sarcopenia， and other factors on the prognosis of elderly patients with acute ischemic stroke（ AIS）. Methods A total of 305 elderly AIS patients hospitalized in the Department of Neurology of the First Affiliated Hospital of Shantou University Medical College from July 2023 to February 2024 were prospectively selected for the study using convenience sampling method. General Information Questionnaire and Strength， Assistance in Walking， Rise from a Chair， Climb Stairs and Falls（ SARC-F）， FRAIL Scale（ FRAIL）， and Barthel Index（ BI） were used to obtain information. Patients were followed up with modified Rankin Scale（ mRS） scores at 3 months after onset， and those with mRS ＞ 2 were included in poor prognosis group， and those with mRS ≤ 2 were included in good prognosis group. Risk factors of poor prognosis in elderly patients with AIS were screened by univariate and multivariate binary Logistic regression. Results There were 89 cases of poor prognosis in 305 elderly patients with AIS， and the incidence of poor prognosis was 29.18%. Univariate analysis showed statistically significant differences between poor prognosis group and good prognosis group in terms of gender， body mass index， indwelling gastric tube， National Institute of Health Stroke Scale（ NIHSS） score， speech impairment， venous thromboembolism assessment， nutritional risk assessment， frailty assessment， sarcopenia， swallowing test assessment， BI score， and total psychological resilience score（ all P＜0.05）. Multifactorial binary Logistic regression analysis showed that prefrailty［ OR=10.321， 95%CI（ 1.909， 55.799）］， frailty［ OR=14.304， 95%CI（ 2.313， 88.455）］， sarcopenia［ OR=2.997， 95%CI（ 1.172， 7.669）］， NIHSS score［ OR=1.188， 95%CI（ 1.045， 1.351）］ and NRS2002 assessment［ OR=5.097， 95%CI（ 1.675， 15.514）］ and BI score［ OR=0.942， 95%CI（ 0.923， 0.961）］ were the influencing factors for poor prognosis in elderly AIS patients. Conclusions Elderly patients with AIS have a high incidence of poor prognosis. Clinical attention should be focused on the patient's prefrailty， frailty， management of sarcopenia， recovery of neurological deficits， nutritional status and activities of daily living.