OBJECTIVES: To estimate the prevalence of high blood pressure (BP) and its relationship with obesity among children and adolescents. METHODOLOGY/PRINCIPAL FINDINGS: In this cross-sectional population (Emirati) representative study, we invited a random sample of 1600 students (grades 1-12) attending 23 out of all 246 schools in the Emirate of Abu Dhabi, United Arab Emirates. But analysis was restricted to Emirati nationals aged 6-17 years. We measured BP, height, weight, waist circumferences (WC), and calculated body mass index (BMI) by standard methods. BP levels ≥ 90(th) percentile but <95(th) percentile and ≥ 95(th) for age, sex, and height (CDC percentiles) were classified as pre-hypertension (pre-HTN) and hypertension (HTN), respectively. Associations between BP, age, BMI, WC, and sex, were investigated by (multiple) linear regression methods. A total of 999 (47% girls) students provided complete results. The prevalence of pre-HTN was 10.5% and 11.4% and the prevalence of HTN was 15.4% and 17.8% among boys and girls, respectively. The prevalence of systolic/diastolic HTN was 14.4%/2.5% and 14.8/7.4% among boys and girls, respectively. BMI CDC percentile was positively correlated with WC percentile (r = 0.734, p<0.01), and both systolic (r = 0.34, p<0.001) and diastolic (r = 0.21, p<0.001) standardized BP. WC percentile was less strongly correlated with standardized SBP (r = 0.255, p<0.01) and DBP (r = 0.175, p<0.01) than BMI. CONCLUSIONS/SIGNIFICANCE: The prevalence of elevated BP, notably systolic was significantly high among the Emirati children and adolescents in Abu Dhabi. High BP was strongly related to body weight, and appears more strongly associated with BMI than WC. Further studies are required to investigate the impact of childhood obesity on HTN.