Marital status is related to cardiovascular disease (CVD) risk factors in Western countries. However, few studies have addressed the relationship between marital status and CVD risk factors in other populations. We investigated lifestyle and CVD risk factors relative to marital status among middle-aged Japanese men. We analyzed baseline data of 40-59-yr-old male workers who participated in the high-risk and population strategy for occupational health promotion (HIPOP-OHP) study. We compared lifestyle and CVD risk factors between men who were married (Group M; n=1,419, mean age 47.9 +/- 5.1 yr) and those who had never married (Group N; n=163, mean age 46.7 +/- 4.3 yr). Men in Group N were more likely to skip breakfast, work more shifts and exercise less. Current smoking rates, as well as average values of diastolic blood pressure (DBP), serum total cholesterol and fasting plasma glucose were also higher in Group N than in Group M. The proportion of participants with three or more CVD risk factors, namely smoking, hypertension, hypercholesterolemia and hyperglycemia was higher in Group N, than in Group M (12.9% vs. 5.0%, p<0.01). The difference between Groups M and N was more evident in the subgroup of living with others, than in the subgroup of living alone. Since men who have never married might be at higher risk for CVD, effort should be made to educate this population about decreasing lifestyle-related risk factors.