Background and Purpose -Using 930 individuals connected in a single pedigree from an isolated population, participants of the Erasmus Rucphen Family (ERF) study, we investigated the heritability of carotid-femoral pulse wave velocity (PWV), carotid intima media thickness (IMT), and carotid plaque score. Methods -PWV was measured between the carotid and femoral arteries as an indicator of aortic stiffness. Common carotid IMT and plaque score, quantifying alterations in arterial wall structure, were measured by ultrasonography. Results -All 3 traits were significantly associated with classic cardiovascular risk factors. Age-and gender-adjusted heritability estimates were 0.36 for PWV, 0.41 for carotid IMT, and 0.28 for plaque score. After adjustment for appropriate risk factors, the heritabilities were 0.26, 0.35, and 0.21 for PWV, IMT, and plaque score, respectively. All heritability estimates were statistically significant (P < 0.001). Taking into account different proportions of variance associated with covariates for each trait, genetic factors explained ≈12%of the total variability for each of the pheno types. Conclusions -To our knowledge, this is the first report on the heritabi lity of PWV. The heritability estimates of IMT and plaque score were similar to those in previous reports. We conclude that genetic factors significantly contri bute to arterial structure and function in this isolated population, presenting the opportunity to locate susceptibility genes related to cardiovascular disorde rs. Background and Purpose -Using 930 individuals connected in a single pedigree from an isolated population, participants of the Erasmus Rucphen Family (ERF) study, we investigated the heritability of carotid-femoral pulse wave velocity (PWV), carotid intima media thickness (IMT) , and carotid plaque score. Methods-PWV was measured between the carotid and femoral arteries as an indicator of aortic stiffness. Common carotid IMT and plaque score, quantifying alterations in arterial wall structure, were measured by ultrasonography. Results-All 3 traits were Age-and gender-adjusted heritability estimates were 0.36 for PWV, 0.41 for carotid IMT, and 0.28 for plaque score. After adjustment for appropriate risk factors, the heritabilities were 0.26, 0.35, and 0.21 for PWV, All heritability estimates were significant significant (P <0.001). Taking into account different proportions of varia nce associated with covariates for each trait, genetic factors explained ≈12% of the total variability for each of the pheno types. Conclusions -To our knowledge, this is the first report on the heritabiity of PWV. The heritability estimates of IMT and plaque score were similar to those in previous reports. We conclude that genetic factors significantly contri bute to arterial structure and function in this isolated population, presenting the opportunity to locate locate resistance genes related to cardiovascular disorde rs.