Excessive and prolonged stress-induced cortisol changes may contribute to or be a marker of essential hypertension. Cortisol is a central component of the stress response, and it interacts with sympathetic and renal mechanisms contributing to increased blood pressure (BP). Although research in individuals with already established hypertension failed to show consistent abnormalities in adrenocortical output, cortisol responses to psychological stress are greater and more persistent in persons at high risk for hypertension relative to low-risk normotensives. Considering the heterogeneous and multifactorial polygenic nature of hypertension and the fact that cortisol affects several BP related processes, and regulates expression of genes involved in BP, it is possible that this hormone is involved in at least a sub-type of hypertension. Recent studies evaluating cortisol tissue sensitivity, cortisol production and cortisol metabolic rate in hypertensionprone persons support the possibility that cortisol may serve as an intermediate phenotype of hypertension. In this review, we discuss components of the stress responses, factors influencing the adrenocortical response, adrenocortical activity in hypertension, and we propose pathways that mediate effects of stress-induced cortisol on BP.