The measurement and evaluation of health-related quality of life during antihypertensive therapy has contributed to physicians' understanding of how patients respond to therapy in terms of physical, psychological, and social well-being. Comparative clinical trials of antihypertensive drug therapies have demonstrated that treatment produces no perceptible improvements in health status. Thus, the "burden" of the therapeutic regimen from the patient's perspective is greatly magnified. Research has also demonstrated that patient expectation and preference are important components of quality-of-life assessment when the purpose of this assessment is to predict or explain human behavior. Drug properties, including mechanism of action and pharmacokinetics, have been shown to influence the impact of drug side effects and the degree to which patients tolerate therapy. Researchers have attempted to standardize the construct of quality of life to have broad applications in health care policy and management; however, clinical research in hypertension should focus on the components of health-related quality of life that influence patient outcomes with regard to behaviors affecting adherence. Antihypertensive agents that maximize patient acceptance and quality of life are now available. Future quality-of-life research should be directed toward learning more about human behavior so that adherence to nonpharmacologic interventions such as diet and exercise will be enhanced.