White-coat hypertension (WCH) is very common: it is present in about one third of subjects with high office blood pressure (BP). A typical patient is a non-smoking female at higher age. Prognostic data are not very reliable because most patients are treated on the basis of elevated office BP; some long-term studies have shown that cardiovascular (CV) risk is increased compared to normotensives. The opposite disorder is masked hypertension (MH). Its prevalence in population-based studies is 13 %. MH is common in males, typically aged between 30 and 50 years, smokers with unfavorable risk profile, and it is also frequent in diabetics. The risk of future cardiovascular events is close to that of sustained hypertensives. It is important to search for MH actively, therefore, we should recommend home BP measurements also to those subjects whose office BP is normal. We do not have any prospective data about treatment of either WCH or MH. In subjects with low CV risk, only nonpharmacologic treatment may be initiated - in this case, however, the patient must be followed closely including out-of-office BP measurements; in those subjects where other CV risk factors and/or target organ damage are present, drug treatment should be considered, but as we have no evidence, only empirical approach is possible.Key words: ambulatory blood pressure monitoring - diagnosis - masked hypertension - prognosis - treatment - white-coat hypertension.