Aims: To determine the prevalence of pre-hypertension (pre-HTN) and hypertension (HTN) in Portuguese adolescents in Lisbon and to ascertain the relationship between blood pressure (BP) levels and the risk factors of gender, obesity, smoking, alcohol consumption, exercise and family history of HTN. Methods: This was a cross-sectional study in a non-randomized sample of 234 adolescents of both sexes, aged between 16 and 19 years. Information on habits and family history of HTN was obtained through a self-completed structured questionnaire. Results: The study included 234 adolescents, mean age 16.4 +/- 0.9 years, 57\% male. The prevalence of HTN was 34\%, higher in males (44\% vs. 21\%, p = 0.001) and 12\% of pre-HTN, higher in females (13\% vs. 10\%, p = 0.001). Higher body mass index was associated with significantly higher prevalence of pre-HTN (normal weight 9.40\%, overweight 16.10\%, and obesity 22.70\%) and HTN (normal weight 30.4\%, overweight 45.2\%, and obesity 45.5\%). With a family history of HTN, the prevalence of HTN and pre-HTN was approximately double (41\% vs. 28\% and 18\% vs. 9\%, respectively). Regular exercise, smoking and alcohol consumption were not significantly associated with BP values. Conclusion: The prevalence of pre-HTN and HTN in the sample studied was high. Of the risk factors evaluated, only gender, obesity and family history of HTN were significantly associated with BP values. (C) 2012 Sociedade Portuguesa de Cardiologia Published by Elsevier Espana, S.L. All rights reserved.