Objective : Silent infarct is more common in healthy elderly people and seems associated with risk of future stroke. However, the prevalence and risk factors of silent infarct are unclear. We investigated the prevalence and risk factors of silent infarct. Methods : 56 first-ever cerebral infarct patients were enrolled in this study. CT images were made of all 56 patients. We divided them into two groups according to the presence of silent infarcts and comparedage, sex, education period, WHR, hypertension, diabetes mellitus, hyperlipidemia, smoking, numbness and weakness of thumb and index finger, neck stiffness, facial spasm, and blepherospasm. Result : Silent infarcts were found in 24 patients(43%). Most infarcts(48%) were located in basal ganglia. Age, sex, education period, WHR, numbness and weakness of thumb and index finger, neck stiffness, facial spasm, and blepherospasm were similar between the two groups. Diabetes mellitus, hyperlipidemia, and smoking were higher in the silent infarct group. Hypertension was higher in the non-silent infarct group. Conclusion : The prevalence of silent infarct in first-ever cerebral infarction patients was 43% and diabetes mellitus, hyperlipidemia, and smoking were higher in silent infarct patients.