OBJECTIVE The role of ambulatory blood pressure monitoring (ABPM) in the management of hypertension is reviewed. CONCLUSIONS ABPM is a fully automated technique in which multiple blood pressure (BP) measurements are taken at regular intervals (usually every 15 to 30 minutes) over a 24-48-hour period, providing a continuous BP record during the patient's normal daily activities. Some experts advocate the use of 24-hour ABPM for all first diagnoses of hypertension and for treatment decision-making. The use of ABPM can improve BP monitoring so that treatment can be optimized more rapidly and more patients can achieve BP targets with appropriate therapy. ABPM may lead to better patient outcomes while requiring less-intensive drug regimens to maintain BP control and reducing treatment costs. By more accurately and reliably measuring BP, especially circadian changes, ABPM has been shown to predict cardiovascular morbidity and mortality and end-organ damage. ABPM is especially beneficial for patients whose hypertension is difficult to diagnose, including the elderly, patients with diabetes, and individuals with resistant hypertension. ABPM is also beneficial for predicting disease severity and prognosis among patients with chronic renal disease, a condition associated with significant cardiovascular risk. Furthermore, ABPM has helped differentiate the 24-hour antihypertensive efficacy of antihypertensive agents among and within differing drug classes and is also useful in drug development for determining optimal dosing. CONCLUSIONS ABPM is an effective method for the accurate diagnosis and management of hypertension and may positively affect clinical outcomes of patients with other risk factors for cardiovascular events.