The goal of this study was to describe the overall genetic contribution of phenotypic variation to cardiovascular disease. The study population included 7,589 family members of 1,891 families, derived from Korean Medical Insurance Corporation. The risk factors considered were systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and high serum cholesterol. The levels of cardiovascular disease risk factors were adjusted for age, gender, smoking and alcohol drinking. Heritability was estimated from the slope of the line linear regression of offspring on mid-parent. All risk factors showed positive familial correlations, and correlations were generally lower for spouses than for parent- offspring pairs. Spouse correlations showed increasing patterns with age. Parents-offspring correlations showed little variation with age, suggesting that the observed correlations with CVD risk factors were primarily due to genetic influences rather than environmental effects. Estimated heritabilities were 26% for BMI, 26% for high serum cholesterol, 19% for SBP, and 9% for DBP. These results highlight the importance of considering genetic factors in studies of cardiovascular risk factors.