Abstract INTRODUCTION: Atherosclerosis of cerebral arteries is the most common etiology of ischemic stroke around the world. This pilot double-center study evaluated risk factors of atherosclerosis in stroke patients in two different racial subtypes. METHOD AND MATERIALS: This prospective clinical study was conducted on 100 consecutive stroke patients in Mackenzie hospital, Canada and 100 consecutive stroke patients in Ghaem hospital, Iran in 2007. The patients were age and sex matched. All of the Canadian patients were from white North American race and all of the Iranian patients were white Persian race. Diagnosis of ischemic stroke was made by stroke neurologists. The frequency rates of hypertension, diabetes, hypercholestrolemia and smoking were detected in the two studied groups. Chi-Square and Fisher tests served for statistical analysis and P < 0.05 was declared as significant. RESULTS: 92 males and 108 females with ischemic stroke were investigated. Hypertension was the most common risk factor of atherosclerosis in all patients followed by hypercholestrolemia, diabetes and smoking. The influence of race on the frequency rate of atherosclerosis risk factors was not significant, P > 0.05. Hypertension was significantly more frequent in Iranian than Canadian males: df = 1, P = 0.023. However, racial difference in the frequency rate of the hypertension was insignificant in the females: df = 1, P = 0.841. The effects of race on frequency rate of other atherosclerosis risk factors was insignificant in each gender separately, P > 0.05. CONCLUSION: There is no significant difference in frequency rate of atherosclerosis risk factors between North American and Persian stroke patients. Keywords: Atherosclerosis, Risk Factors, Stroke, Race.