Objective: to evaluate the prevalence of high blood pressure in fat or overweight children and adolescents and its associated factors. Methods: Cross-sectional study including 200 children and adolescents between two and 18 years old. It was measured the abdominal circumference, blood pressure, weight and height. The systolic and diastolic blood pressure were considered high when equal or higher than 90th percentile. The value of the blood pressure in the 25th, 50th and 75 th percentiles were described according to age groups, sex, nutritional state and abdominal circumference. To check the association between high blood pressure and clinical variables it was used qui-square tests and a significant level of 5%. Results: The majority of children and adolescents (70.5 %) had high blood pressure: 6% showed an increase only in the systolic blood pressure, 33% in diastolic blood pressure and 31.5 % in both. Systolic blood pressure values were higher observed in individuals with severe obesity and increased waist circumference, as well as those of the male sex and in the group of adolescents. Among those who had high blood pressure, the normal maximum limit of the systolic blood pressure was observed in the 50th percentile and for the diastolic in the 75 th percentile. The high systolic blood pressure was associated with adolescents with severe obesity. Conclusion: The high prevalence of high blood pressure observed in this study indicates the need to implement policies and actions oriented towards the prevention and control of obesity and its comorbidities, as the case of high blood pressure.