This study aimed to clarify the association between malnutrition and improvement of swallowing ability during rehabilitation of stroke patients.This was a retrospective cohort study.One hundred eighty-eight older adults with oropharyngeal dysphagia after stroke who were admitted to a rehabilitation hospital.The International Dysphagia Diet Standardization Initiative Functional Diet Scale (IDDSI-FDS) was used to assess swallowing ability. The Global Leadership Initiative on Malnutrition (GLIM) definition was used to diagnose malnutrition. The primary outcome was IDDSI-FDS score at discharge.The mean age of the patients was 78.9 ± 7.7 years, and 36.7% were women. A total of 122 (64.8%) patients were diagnosed with malnutrition. Compared with those without malnutrition, malnourished patients had more severe dysphagia on admission. After adjusting for confounders, malnutrition was an independent contributor to the IDDSI-FDS scores at discharge (standardized coefficient: -0.165, P = .011).In patients with oropharyngeal dysphagia after stroke, malnutrition at admission inversely affected their swallowing ability at discharge. Dysphagia rehabilitation, including early nutritional intervention, may be effective in the recovery of swallowing ability.