objectives: to evaluate the insulin response to an oral glucose load in children and adolescents with overweight and obesity. methods: two-hundred subjects attending the out-patient endocrinology clinic of the hospital jm de los ríos, caracas, venezuela, with unspecific symptoms of hypoglycemia or body weight excess were selected. hypoglycemia and/or carbohydrate metabolism abnormalities were ruled out. subjects were categorized according pubertal stage and body mass index (bmi); group a: pre-pubertal: (tanner i), bmi p90; group d: adolescents (tanner ii-v), bmi> p90. plasma glucose and insulin were measured at baseline and 30, 60 and 120 minutes after oral glucose load (1.75 g/kg). results: basal insulin was significantly higher in adolescents and groups with abnormal body weight, compared with pre pubertal and normal weight respectively. all groups showed a peak insulin response at 30 min post oral glucose load; the insulin response was higher as bmi and pubertal stage increased with the highest values in adolescents and body weight excess (p<0,01). no significant differences were observed according diabetes mellitus family history. conclusions: our results suggest that oral glucose tolerance test might be useful in children and adolescents with body weight excess in order to identify the subjects at risk of metabolic disorders leading to improve prevention strategies in this young population.