BACKGROUND: Adiponectin is an abundant adipocyte-secreted hormone that modulates a number of metabolic processes and is correlated to various metabolic disorders. Pediatric reference levels are needed for the risk stratification and interpretation of individual serum adiponectin levels. METHODS: A total of 1193 healthy, non-obese Danish schoolchildren (730 girls, 463 boys) aged 6-18years (median 11.9) were examined by trained medical staff. Total serum adiponectin concentrations in venous fasting blood samples were quantitated by a DuoSet® ELISA human Adiponectin/Acrp30 (R&D Systems) following optimization. RESULTS: In a generalized linear model adjusted for BMI SDS, total serum adiponectin concentrations were correlated to age in girls (p<0.0001) and boys (p=<0.0001) and for both sexes combined (p<0.0001). No significant difference between sexes was found. Reference intervals were calculated using age as a continuous variable. The best fitted reference curve for both sexes was: 50th percentile: Y=-0.1478∗X+6.046; 2.5th percentile: Y=-0.06256∗X+2.34; 97.5th percentile: Y=-0.4086∗X+22.39, where Y=adiponectin in μg/mL and X=years of age (from 6 to 18years). CONCLUSION: We developed a pediatric reference levels for total serum adiponectin in a sample of 1193 Danish children and adolescents aged 6-18years. A correlation with age was demonstrated in children, but no significant difference was seen between the sexes.