This is the first clinical study evaluating the relation of serum omentin 1 levels with anthropometric and metabolic parameters in obese children with a particular interest to identify the possible role of omentin 1 in childhood obesity and related metabolic disturbances. The study included obese children with a body mass index (BMI)>95th percentile and healthy children with a BMIth percentile. The healthy and obese subjects had similar age and gender distribution. Glucose, insulin, lipid profile, and omentin 1 levels were measured to evaluate the metabolic parameters. 49 obese children who applied to our department with complaint of weight gain and 30 healthy age and sex matched subjects were enrolled. In obese children BMI, body mass index-standard deviation score (BMI-SDS), systolic blood pressure (SBP), diastolic blood pressure (DBP), mid-arm circumference (MAC), triceps skin fold (TSF), waist circumference (WC), homeostasis model assessment-insulin resistance (HOMA-IR), serum insulin, and triglyceride levels were higher whereas omentin-1 levels were lower than control subjects (p0.05). Additionally, although statistically insignificant, patients with IR (n=31) had lower omentin-1 levels compared to obese children without IR (n=18). Our data indicates that serum omentin 1 levels are i) lower in obese children and ii) negatively correlated with BMI, WC, HOMA-IR and insulin levels suggesting that omentin 1 might be a biomarker for metabolic dysfunction also in childhood and adolescence. Lower omentin 1 levels tended to be associated with insulin resistance however this association failed to reach statistical significance. Further studies in larger populations are needed to better-define the relation of omentin 1 and insulin resistance in obese children.