Cerebral infarction (CI) is still a leading cause of death in Japan. Thus, the management of risk factors for CI as primary prevention is one of the most important tasks in multiphasic health testing and services. To determine whether carotid intima-media thickness (IMT) is a risk for CI, ultrasonographically assessed carotid IMT was compared between normal subjects (N) and subjects with asymptomatic CI (ACI) in 243 subjects who underwent human brain dry dock. ACI was found in 68 people (28.0%). Age, body mass index, and mean blood pressure were higher in ACI than in N. Also, atherogenic index was higher in ACI than in N. Carotid IMT was significantly thicker in ACI than in N. Furthermore, incidence of atherogenic plaque in ACI was significantly higher than that in N. In conclusion, not only aging, obesity, blood pressure, and plasma lipids, but also carotid IMT may be a risk for ACI.