In this pilot study, we sought to compare the vasodilatory and hemodynamic properties of the peripheral vasculature in the forearms of young, healthy African-American females to similarly matched white females. We used high-resolution ultrasound of the brachial artery to evaluate 11 African-American females and 8 white females. When normalized to nitrate-induced dilation, endothelium-dependent dilation was reduced in young African American females compared to white females (0.6 in African American females compared to 1.0 in white females). These results indicate the need for a larger study to examine this phenomenon.