OBJECTIVES: The aim of our current study was to find out whether a weekly or seasonal variation can be revealed in the onset of a transient ischemic attack (TIA) in Hungary during a four year study period, and whether the occurrence of a TIA is influenced by age or sex. METHODS: The study was performed on patients received treatment at neurological departments in Hungary between 2002 and 2005, and diagnosed with TIA (N=4898). Data was taken from the nationwide database of the National Health Insurance Fund Administration (OEP), in accordance with the International Classification of Diseases (ICD) (ICD codes G4580, G4590). RESULTS: Based on our results, the onset of cerebrovascular diseases, such as a transient ischemic attack (TIA), shows a weekly and seasonal variation. With consideration to seasonal variation, the peak period of TIA is during the months of spring, with lowest number of events during the summer. There was a significant difference in the number of events during seasons (p<0.01). The weekly peak of TIA-morbidity was during the first day of the week, on Monday, showing a gradually decreasing tendency until Sunday. Differences between sexes were only found in the weekly distribution of number of events. The difference between age-groups proved to be significant only in weekly analysis and the decrease on weekends is significantly higher in patients aged over 65 years (p<0,01). CONCLUSION: In summary, the results of our study reveals, that the occurrence of TIA shows a certain variation with consideration to seasons and the days of the week.