Background: This study aimed to clarify the association between the co-existence of possible sarcopenia (PS) and dysphagia in patients with acute stroke and the functional outcomes 12 months after stroke. Methods: This multicenter retrospective cohort study was conducted on patients with stroke admitted to two acute care hospitals in Japan between November 2020 and October 2023. PS was defined based on grip strength (males <28 kg, females <18 kg) and calf circumference (males <34 cm, females <33 cm) on admission. Dysphagia was defined as a Functional Oral Intake Scale score of less than 4. The outcome was defined as a composite of either poor functional outcome (modified Rankin Scale [mRS] score of 3–6) or failure to recover to the premorbid mRS at 12 months after stroke onset. Modified Poisson regression analysis was used to examine the association between the co-existence of PS and dysphagia and poor functional outcomes. Results: This study included 604 patients (median age 76 years; 367 men). Compared with the non-PS and non-dysphagia group, the PS and dysphagia group had a higher proportion of poor functional outcomes. Subsequently, modified Poisson regression analysis was performed. The interaction between PS and dysphagia was significantly associated with poor functional outcomes (risk ratio=4.348, 95% confidence interval 2.683–7.046). Conclusion In patients with acute stroke, the co-existence of PS and dysphagia was associated with poor functional outcomes 12 months after stroke. Future multicenter prospective interventional studies are required to clarify the effectiveness of multifaceted intervention programs in high-risk patients.