OBJECTIVE:This study was initiated to investigate if spousal concordance in metabolic syndrome (MS) components exist in Japan. METHODS:In all, 756 couples (mean age: 48.9 and 47.3 years for husbands and wives, respectively) were identified. Each subject was classified as an MS, MS reserves (MSRES) or no risk of MS (NonMS) case after Japanese Ministry of Health, Labour and Welfare (JMHLW) criteria. Criteria of the National Cholesterol Education Program and of the Joint Interim Statement were also applied. RESULTS:With Japanese Ministry of Health, Labor and Welfare (JMHLW) criteria, MS, MSRES and NonMS cases accounted for 11.9, 14.7 and 73.4 % in husbands and 1.6, 3.7 and 94.7 % in wives. Waist circumference (WC), body mass index (BMI), systolic blood pressure (SBP) and hemoglobin A1c (HbA1c) showed significant correlation (p < 0.01). Correlation was also significant (p < 0.05) for mean blood pressure (MBP) and fasting plasma glucose (FPG). When adjusted for age, correlations were significant only for WC, BMI and HbA1c. Furthermore, none of the correlation coefficients were greater than 0.2. Logistic regression analyses did not suggest significant mutual influence in MS status between the couples. CONCLUSIONS:Spousal concordance in MS components was detected for WC, BMI, SBP, MBP, FPG and HbA1c, but the correlation was generally weak and modest in Japanese couples.