Objective: Findings from adult studies suggest that tronco-conical cuffs should be used for accurate blood pressure (BP) measurement in obese individuals with large arm circumference (AC). The aim of the present study was to examine differences in office blood pressure (BP) levels using conical cuffs compared to standard-shaped cylindrical cuffs in obese children and adolescents. Design and method: We performed an observational study enrolling 37 obese children and adolescents consequently recruited from the outpatient clinics of the Obesity Unit at General University Hospital Consortium of Valencia. The device used for the office BP measurements was OMRON HBP-1320 (HBP-1320-E). Middle AC was measured in all participants and the appropriate cuff size was selected among five sizes of conical and three sizes of regular cylindrical cuffs. Results: Mean participants’ age was 11.8±2.5 years, mean BMI was 28.8±3.4 kg/m2, BMI z-score was 2.1 ± 0.3, and mean AC was 30.0±3.6 cm. There was no statistical significance in BP levels measured by cylindrical compared to conical cuffs (mean difference cylindrical-conical cuff was -0.22±6.55 mmHg for SBP, -0.02±0.81 for SBP z-score, -0.70±4.95 mmHg for DBP, and -0.06±0.44 for DBP z-score). The analysis was repeated after excluding participants aged <9 years old, retrieving similar results. A significant positive association was found between the measurements obtained by cylindrical and conical cuffs in both mean and z-score SBP and DBP values (p <0.001). Bland-Altman analysis showed good agreement, with 94.6% of the values for all BP parameters, lying between the limits of agreement. No proportional bias was detected (p >0.05). Conclusions: The use of conical cuffs resulted in similar office BP levels in obese children and adolescents suggesting no advantage in enhancing tolerability and accuracy of office BP measurement in these patients. Although conical cuffs may be considered an alternative for office BP measurements in obese children, their reliability should be confirmed in larger populations and different settings. Acknowledgments: This abstract is based on the work of the COST Action HyperChildNET (CA19115), with the support of COST (European Cooperation in Science and Technology) and the Horizon 2020 Framework Program of the European Union.