Objective: The aim of this study was to assess the prevalence of white coat hypertension in children and adolescents Design and methods: A cross sectional study was carried out in 142 patients 82 boys and 60 girls aged 12-19 years mean 16,27±2,8. To all patients were performed office blood pressure measurement (BP), Ambulatory Blood Pressure Monitoring (ABPM) and echocardiography. White Coat Hypertension (WCH) was diagnosed when office blood pressure measurement were 95 th percentile > for sex and age or >140/90 for those >18 years, and systolic and diastolic daytime values obtained by ABPM were <95 th percentile for sex and age or <135/85 mm Hg for those >18 years. All patients after follow up one year were undergoing second ABPM Results: At baseline we detected 15 patients with white coat hypertension. This condition represented 56% of the office hypertension. The prevalence of WHC hypertension was higher in the males than females (14,5% Vs 5,7% p=0,03) The mean age was not different to normotensive and hypertensive groups (16,17±2,1 vs 16,20±2,2 years and 16,19±2.09). During follow up 6 of 15 patients become normotensive 6 developed sustained hypertension and 3 had persistent White coat hypertension When compared patients that became normotensive than patients that developed sustained hypertension and had persistent WHC had higher baseline office systolic BP (142,03±7,3 vs 131,2±4,3 p<0,001) higher baseline daytime ambulatory systolic BP 127,53±5,73 vs 120,33±4.63 p<0,05. Conclusion: Children and adolescents with white coat hypertension should be followed closely due to its tendency to developed sustained hypertension. Higher values of systolic blood pressure associated with the development of hypertension