Although intensively discussed and finally accepted in the last years "white coat phenomenon" (WCF) still raises the question of the benefit of diagnosing it in pediatric patients as its possible link with the subsequent essential hypertension is not clear yet. This study included 1068 schoolchildren (aged 10 to 16 years) submitted to a screening program for detecting the in time variations of blood pressure (BP). When the study was started WCP was present in 60 children (5.6%) and when it ended its frequency raised to 8.73%. In 14 of 60 children (23.3%) WCP progressed to borderline or confirmed essential hypertension, incidence higher that that of similar forms of essential hypertension occurring in patients with normal BP levels (20 of 955 = 2.05%). With time, the frequency of borderline and confirmed essential hypertension has also increased: 5.11% at the first determination to 7.85% at last one. The high frequency of WCF and associated with the high frequency of its progression to essential hypertension support the idea that WCP has a predictive value for the development of essential hypertension. An early diagnosis and the prevention of other risk factors may lower the frequency of essential hypertension in adults.