Background and Objective: Arterial hypertension (AH) subtypes in the pediatric population may represent distinct pathophysiological subsets, potentially allowing for more targeted interventions and improved blood pressure (BP) management. Emerging evidence suggests that various hemodynamic mechanisms may underlie hypertension development across different age groups. Moreover, overweight and obesity, are closely linked to hypertension and other risk factors. Therefore, this study aims to investigate the relationship between body mass index (BMI) and (AH) subtypes in the pediatric population. Methods: A cross-sectional study was conducted, involving 195 records from 189 children referred to an outpatient cardiology center due to suspected BP abnormalities. Each participant underwent 24-hour ambulatory blood pressure monitoring (24-h ABPM) using a device validated. Demographic, clinical, and anthropometric data were collected. The American Heart Association (2022) criteria were utilized to ensure accurate 24-h ABPM recordings and to classify AH subtypes based on average BP, including: i) isolated diastolic hypertension (IDH); ii) non-divergent systolic-diastolic hypertension (ND-SDH) (pulse pressure [PP]<50 mmHg); iii) divergent systolic-diastolic hypertension (D-SDH) (PP>50 mmHg); and iv) isolated systolic hypertension (ISH). BMI Z-Score was calculated using Colombian reference tables, and nutritional status was determined based on World Health Organization recommendations. Results: Among the participants, 46.0% were male, with a distribution of nutritional status showing 3% underweight, 37% normal weight, 30% overweight, and 30% obese. The average age was 12.3±3.0 years (range: 5-17 years). 24-h ABPM records revealed that 34.0% had normotension, 33.0% had IDH, 16.0% had ND-SDH, 13.0% had D-SDH, and 3% had ISH. The ANOVA test indicated significant differences in BMI Z-Score values among AH subtypes (P value <0.001) (Figure). Conclusions: BMI is related with AH subtypes in children. Specifically, BMI tends to be higher in D-SDH and ISH, which could be characterized by a hyperdynamic state marked by increased activity of the sympathetic nervous system. This finding may help to elucidate the pathophysiology of hypertension in obese children.