Abstract INTRODUCTION: Transient ischemic attacks (TIA) are warnings of future stroke. There is no difference in risk factors, pathophysiology and prevention between TIA and brain infarction. methods: Consecutive patients with brain infarction admitted to Ghaem Hospital, Mashhad, Northeastern Iran, were enrolled in a prospective study during 2006. Diagnosis of ischemic stroke was established by a neurologist who also obtained history of TIA and vascular risk factors. All of the stroke patients underwent a standard battery of diagnostic investigations and etiology of ischemic stroke was determined by the Practical Iranian Criteria classification. Fisher’s exact test was used for statistical analysis. results: 348 stroke patients (186 women, 162 men) were studied. History of TIA was present in 42 patients (29 women, 13 men), i.e. 12% of the stroke patients. TIA was more common in women (df=1, P=0.02). The frequency of hypertension, diabetes and ipsilateral carotid stenosis was not significantly different between patients with history of TIA and other stroke patients (P=0.87, P=0.64 and P=0.61, respectively). Hyper-cholesterolemia and smoking were significantly more frequent in stroke patients with history of TIA (P=0.011 and P=0.014, respectively). The frequency of TIA was not significantly different among patients with lacunar, versus large vessel territory infarcts (df=1, P=0.84). There was no significant difference in the frequency of various stroke etiologies in patients with and without history of TIA (df=4, P=0.61). CONCLUSIONS: Stroke patients with history of TIA have vascular risk factors similar to other stroke patients. A positive history of TIA does not affirm any specific etiology of ischemic stroke. Keywords: Risk factors, etiology, transient ischemic attacks.