Hypertension, a major risk factor for cardiovascular disease worldwide, remains inadequately diagnosed and treated, particularly in certain at-risk populations. Hypertension, often in association with other factors, increases the risk for the development of coronary artery disease (CAD). In turn, CAD increases the risk for related morbidity and mortality and presents treatment challenges. The chronobiology of many cardiovascular events offers a pathway for selecting optimal therapy for the hypertensive patient with CAD. Choosing a long-acting agent that achieves high plasma drug levels during critical hours may reduce the risk for cardiovascular morbidity and mortality. © 1999 American Journal of Hypertension, Ltd.