OBJECTIVE To determine, in a school-based sample of children and adolescents, aged from 7 to 17 years, of both gender, in public and private schools, the frequency of students already submitted to blood pressure measure. METHODS A cross-sectional study was carried out, sampling from a population pool of elementary and middle schools, randomly selected. The sample was calculated based on the expected prevalence of hypertension for the age group. Data were collected through a questionnaire. Blood pressure was measured twice and hypertension was defined as mean systolic and/or diastolic blood pressure over the 95th percentile. Independent variables studied: sex; age groups; economic status; public/private school. RESULTS The final sample included 1253 students. The response rate was 97%: 1215 students; 531 males; mean age 12,4 +/- 3 years (236 from 7 to 9 years; 638 from 10 to 14 years; 341 from 15 to 17 years). Prevalence of hypertension was 7.7%; 348 students (29%) were already submitted to blood pressure measures (54% once; 35% 2 to 4 times; 11% 5 or more times). High economic status, private school and adolescent group were significantly associated to previous blood pressure measure. CONCLUSIONS Despite of pediatric consensus statements and guidelines recommendations about importance of blood pressure measure at every examination after age 3 years, there is a very low frequency of this practice (29%) in children and adolescents.