With recent technological advances, 24-hour ambulatory blood pressure (BP) monitoring (ABPM) has become a useful tool for the evaluation, diagnosis, and management of hypertensive children. It provides a more accurate representation of an individual's BP rather than intermittent casual or office BP measurements. Hence, ABPM is being used more often to assess the BP of children. In this comprehensive review, we provide the reader with the available literature on ABPM, discuss the advantages and limitations of ABPM, and the interpretation of ABPM data. The role of ABPM in various clinical conditions and hypertension research in children is presented.