The prevalence of white coat hypertension, which is defined by hypertension in the physician's office, and normotension at other times, may be as high as 30% in a hypertensive population. Since white coat hypertension is associated with a low degree of end-organ damage and, accordingly, a potential favourable prognosis, the use of ambulatory blood pressure recordings has increased with the aim of identifying hypertensive subjects who may not need medical treatment. White coat hypertension is, however, not yet clearly defined, and there seems to be evidence that such subjects may have reduced vasodilator capacity. Low arterial compliance, a feature associated with hypertension in the elderly, seems to be another characteristic. Hence, although the prognostic significance of white coat hypertension has not yet been completely defined, there is accumulating evidence that ambulatory blood pressure recordings may serve as an important tool in the risk assessment of subjects with arterial hypertension.