Arterial hypertension is a pathology of multifactorial origin, clinically defined as a disorder of elevated blood pressure, characterized by high systolic and/or diastolic blood pressure levels. It can be asymptomatic or symptomatic, with manifestations of headache, tinnitus, nervousness and palpitation. This disorder can increase the risk of heart, neurological, kidney and vascular problems. As it is considered a silent pathology, it is necessary to check blood pressure before dental procedures that involve the use of vasoconstrictors, to avoid reactions and hemodynamic effects. This disease is still considered a major public health problem, affecting around 20% of the population. Several risk indicators contribute to the development of hypertension in children and adolescents, such as family history, obesity and a sedentary lifestyle. The aim of this study was to investigate the prevalence of undiagnosed hypertensive adolescent patients seeking care at the UEA dental polyclinic. The study was carried out between October 2011 and September 2012, with a sample of 93 patients.