Since the use of ambulatory blood pressure monitoring (ABPM) in the beginning of the 70's, our perception of blood pressure based only on office blood pressure has been challenged. Indeed, more specific phenotypes such as white coat hypertension, masked hypertension or different circadian patterns of blood pressure have been described and studied. This has resulted in increased use of ambulatory blood pressure measurements for diagnostic and therapeutic purposes. The main focus of this paper is night-time blood pressure. We review, in a non-systematic way, the diagnostic, the prognostic and therapeutic utility of night-time blood pressure. Finally, studies in which antihypertensive drugs are given at night will be presented.