A cross sectional study was carried out in order to investigate the association between excess weight based on body mass index (> or = p85 Must scales), and high diastolic and sistolic blood pressure (> or = p90 Task Force Blood Pressure Control in Children scales). The sample consisted of 1253 male and 1358 female, aged 6 -18 years in the city of Medellín, Colombia. Excess weight was observed in 14.3% of males and 13.7% of females, with higher prevalence at 6 to 9 years old in any gender. Diastolic high blood values were significantly higher in males (4.9%) when compared to females (2.9%) (p = 0.007), and high sistolic values were found similarly in males (1.6%) and females (1.0%) (p = 0.203). This study confirmed the statistically significant association between high body mass index (> or = p85) and high sistolic (RP 4.04; IC 2.03-8.04) and diastolic (RP 3.44; IC 2.32-5.09) blood pressure.