Ambulatory blood pressure monitoring (ABPM) is a valuable tool to evaluate the blood pressure pattern, to identify hypertensive patients, to diagnose white coat and masked hypertension and in situations in which a tight control of hypertension is crucial. This is an update of 1999 consensus recommendations about the use to ABPM, considering that there is new evidence concerning its benefits, and the clinical experience with its application has increased. Equipment programming, its installation, the interpretation and analysis of the data are described, and a report sheet for patients is included. New recommendations have been added to the accepted indications. Normal blood pressure ranges for children and pregnant women have been replaced by new data.