There is some evidence that blood pressure is higher in persons with darker skin tone but the reasons for this remain unclear. When seen in minorities, the positive relationship between darkness of skin and blood pressure invites hypotheses about potential mediators of the relationship. We investigated the relationship in Hispanics of primarily Mexican descent and included measures of hostility, locus of control and perceived racial discrimination hypothesized to mediate higher blood pressure. Regression analysis revealed no relationship between darkness of skin and blood pressure but correlations between hypothesized mediators were significant and explicable. Cynical hostility and external locus of control were positively associated with perceived racial discrimination. We reasoned that the chronic experience of racial discrimination reinforces the perception of discrimination and feeds both external locus of control and cynical hostility despite no corresponding unfavorable effect on blood pressure. (Contains 1 table.)