Obesity in children and adolescents has increased alarmingly, with significant implications for cardiovascular health. Childhood obesity is a strong predictor of cardiovascular risk (CVR) and mortality, contributing to the development of metabolic syndrome (MS). MS in children is associated with biochemical and inflammatory factors that impair vascular function. Non-invasive assessment of vascular function in children can detect endothelial dysfunction and arterial stiffness early, before clinical atherosclerosis. Obesity-related insulin resistance and endothelial dysfunction are linked to premature atherogenicity and adult CVR factors. Adipose tissue factors that interfere with insulin action and endothelial function are major precursors of CVR. Childhood obesity has major metabolic and cardiovascular consequences, influencing the development of atherosclerosis and lifelong CVR. Programs combining diet and exercise for overweight/obese children are essential to improve vascular function and metabolic disorders. These should be complemented by primary prevention against childhood obesity. Childhood obesity is associated with increased arterial stiffness and endothelial dysfunction, which are early signs of atherosclerosis. Vascular function can be assessed using ultrasound and other non-invasive methods, revealing early atherogenesis. Arterial stiffness is closely linked to early atherosclerosis and is more strongly associated with visceral adiposity than BMI. Non-invasive vascular function assessment is a useful surrogate for cardiovascular disease. Endothelial dysfunction is an early sign of increased CVR and predicts cardiovascular events. In obese children, endothelial dysfunction is related to obesity severity and insulin resistance. Adiponectin and leptin are key biomarkers of insulin resistance and vascular function. Childhood obesity is associated with low-grade inflammation, which contributes to MS and CVR. Prevention strategies should focus on early intervention to reduce obesity and its associated risks. Primary prevention is crucial to address the growing obesity epidemic in children. Childhood obesity is linked to increased cardiovascular risk factors, including hypertension, dyslipidemia, and insulin resistance. Early intervention through diet and exercise is essential to prevent long-term cardiovascular complications. The relationship between childhood obesity, MS, and CVR is complex, with multiple factors contributing to the development of atherosclerosis. Effective prevention strategies are needed to reduce the burden of obesity and its associated health risks in children.Obesity in children and adolescents has increased alarmingly, with significant implications for cardiovascular health. Childhood obesity is a strong predictor of cardiovascular risk (CVR) and mortality, contributing to the development of metabolic syndrome (MS). MS in children is associated with biochemical and inflammatory factors that impair vascular function. Non-invasive assessment of vascular function in children can detect endothelial dysfunction and arterial stiffness early, before clinical atherosclerosis. Obesity-related insulin resistance and endothelial dysfunction are linked to premature atherogenicity and adult CVR factors. Adipose tissue factors that interfere with insulin action and endothelial function are major precursors of CVR. Childhood obesity has major metabolic and cardiovascular consequences, influencing the development of atherosclerosis and lifelong CVR. Programs combining diet and exercise for overweight/obese children are essential to improve vascular function and metabolic disorders. These should be complemented by primary prevention against childhood obesity. Childhood obesity is associated with increased arterial stiffness and endothelial dysfunction, which are early signs of atherosclerosis. Vascular function can be assessed using ultrasound and other non-invasive methods, revealing early atherogenesis. Arterial stiffness is closely linked to early atherosclerosis and is more strongly associated with visceral adiposity than BMI. Non-invasive vascular function assessment is a useful surrogate for cardiovascular disease. Endothelial dysfunction is an early sign of increased CVR and predicts cardiovascular events. In obese children, endothelial dysfunction is related to obesity severity and insulin resistance. Adiponectin and leptin are key biomarkers of insulin resistance and vascular function. Childhood obesity is associated with low-grade inflammation, which contributes to MS and CVR. Prevention strategies should focus on early intervention to reduce obesity and its associated risks. Primary prevention is crucial to address the growing obesity epidemic in children. Childhood obesity is linked to increased cardiovascular risk factors, including hypertension, dyslipidemia, and insulin resistance. Early intervention through diet and exercise is essential to prevent long-term cardiovascular complications. The relationship between childhood obesity, MS, and CVR is complex, with multiple factors contributing to the development of atherosclerosis. Effective prevention strategies are needed to reduce the burden of obesity and its associated health risks in children.