Purpose: This study was done to evaluate nursing guidelines for patients with acute stroke, developed by adapting the guidelines of Registered Nurses Association of Ontario, Canada to clinical settings on a large scale and evaluating the effectiveness as a research study. Method: The general characteristics of the 319 patients and the effectiveness of guideline application were evaluated in terms of structure, process, and outcome using questionnaires on the guidelines application with reference to the medical records of patients with acute stroke hospitalized on a ward of the stroke center of S General Hospital in Seoul. Results: Structures as a guidance system for assessment were consistent with the recommendations. With respect to the process of the guidelines, for items on nursing assessment, improved performance was found to be statistically significant. For outcomes of the guidelines, complications occurred in 8 patients (5.3%) prior to application of the guidelines and 11 patients (6.5%) after application of the guidelines, but this result was not statistically significant (p=.841). Conclusion: The results of the study indicate that for the effectiveness of the guidelines, accessibility to the guidelines and effectiveness of quality improvement need to be evaluated, in addition to complications of a stroke.