Purpose: The purpose of this study was to demonstrate effects of a critical pathway (CP) for stroke patients seen in emergency rooms (ER). Method: The CP developed by the CP committee consisted of 8 criteria: behavior of doctors and nurses, laboratory tests, Image testing, medication, treatment, activity, and nutrition. According to application of CP, a control group (n=17) and experimental group (n=17) were defined. Time was checked by the electronic medical records. Result: Use of CP for stroke patients in the ER, resulted in a decreased length of stay in ER (t=2.341, p=.026), and time required for image testing (t=2.623, p=.021), and an increased number of patients using rtPA ($x^2$=4.802, p=.049). Time required for neurology doctor contact, for neurology doctor to see patient in the ER, and for report of blood tests decreased, but there were no statistical significance. Conclusion: Quick responses are most important in the ER, so CP for these patients is a very effective patient management tool. To reduce delay in stroke diagnosis, continuous education programs for similar symptoms are necessary. CPs for other patients in the ER should be developed, and studies on cost and satisfaction, as well as length of stay, should be done.