Objectives : The weekly variation of ischemic stroke incidence according to the age and sex. Methods : 977 consecutively admitted patients (521 males and 456 females) in a single stroke center from 2006 to 2008. All cases were confirmed with standardized criteria. We used the independent t-test and $x^2$ test in statistical methods. Results : The results demonstrated significant weekly variations of ischemic stroke incidence showing higher incidence on Saturday, Monday and Tuesday and lower incidence on the other days. Difference of ischemic stroke incidence was also shown between transit days, which included the transit days from the weekend to the week and vice versa, and non-transit days. Those aged older than 60 years and females showed more significant differences of weekly variation on transit days than on non-transit days. Conclusions : Ischemic stroke incidence has significant weekly variation, and transit days have higher incidence than non-transit days. Further study is required to identify the general weekly variation by multi-center trial.