Background and Purpose-We describe the prevalence of cardiovascular risk factors at stroke onset in men and women of all ages. Methods-A registry started in 2001, designed to register all hospitalized stroke patients in Denmark, now holds 40 102 patients with first-ever ischemic stroke. Patients underwent evaluation including stroke severity (Scandinavian Stroke Scale), CT, and cardiovascular risk factors: hypertension, atrial fibrillation, diabetes mellitus, intermittent arterial claudication, previous myocardial infarction, body mass index, smoking, and alcohol consumption. We estimated the independent effect of gender and age on prevalence of cardiovascular risk factors and calculated age and gender-specific prevalence rates for each risk factor. Results-The register contained 47.9% women and 52.1% men. Men had more often diabetes mellitus, previous myocardial infarction, intermittent arterial claudication, and over the limit alcohol consumption. Women had more often hypertension and obesity. Atrial fibrillation and smoking were equally frequent in both genders. Age stratification revealed that the lifestyle cardiovascular risk factors smoking, alcohol, and obesity were more common in the younger patients with stroke (Ͻ60 years), whereas prevalence of hypertension, diabetes mellitus, myocardial infarction, intermittent arterial claudication, and, in men, also atrial fibrillation decreases in the elderly (Ͼ70 to 80 years), the decrease being generally more pronounced in men than in women. Conclusion-Cardiovascular risk factors were generally more prevalent in men. Lifestyle cardiovascular risk factors were more common in the young. Prevalence of hypertension, diabetes mellitus, coronary heart disease, and, in men, also atrial fibrillation go down after the age of 70 to 80 years. (Stroke. 2010;41:2768-2774.)