Based on waist circumference and the number of risk factors making up criteria for metabolic syndrome, we divided subjects - 99 men and 103 women - into three groups, i.e., those with fewer than 2 risk factors (RF<2 group), nonmetabolic syndrome subjects with 2 or more risk factors〔RF≥2+MetS(-) group〕and metabolic syndrome patients〔MetS(+) group〕, and studied the progress level of atherosclerosis and the frequency of cardio- and cerebrovascular disease. Both the RF≥2+MetS(-) and MetS(+) groups had significantly more progressive atherosclerosis and more frequent cardio- and cerebrovascular disease than the RF<2 group. Although the MetS(+) group had significantly higher HOMA-R than the RF≥2+MetS(-) group, no significant difference was seen between the RF≥2+MetS(-) and MetS(+) groups in the progression of atherosclerosis or the frequency of cardio- and cerebrovascular disease. We must therefore recognize that many patients have a risk for cardio- and cerebrovascular diseases equivalent to metabolic syndrome patients in nonmetabolic syndrome persons.