This report reviews the evidence for and against clinical use of ambulatory blood pressure monitoring (ABPM) on a large scale. Such monitoring is supported by a number of data, among which is that the end-organ damage associated with hypertension correlates more with 24-h average blood pressure than with clinic blood pressure, the correlation becoming even closer with addition of blood pressure variability values. However, the evidence thus far collected is largely cross-sectional. Furthermore, ABPM devices have limited accuracy and the procedure has a high cost. Therefore, while prospective studies on the prognostic value of ambulatory blood pressure are awaited, use of this approach should be restricted to a limited number of clinical circumstances (e.g., identification of white-coat hypertension) and used only in specialized centers.