Dehydroepiandrosterone sulfate (DHEAS) is an adrenal steroid which has been inversely associated with development of atherosclerosis. We estimated heritability of serum DHEAS levels in 564 related Mexican Americans. We found a significant heritability for DHEAS (h2 = 0.39, p < 0.001). Measures of alcohol consumption, reproductive status, body composition, and HDL3 levels showed significant relationships with serum DHEAS levels. Sex and age were significantly associated with the mean, but not the genetic variance, of DHEAS levels. The results of this study demonstrate a significant genetic influence on steroid concentration and help to quantify the factors contributing to cardiovascular disease risk in Mexican Americans.