Background: Leptin and adiponectin are two key adipocyte secreted hormones and both are involved in several essential physiological mechanisms. Due to their central role in energy homeostasis their ratio, the leptin/adiponectin ratio, is believed to be a marker of metabolic derangement. Pediatric reference values are needed for the risk stratification of individual-measured ratios. Methods: Blood samples were drawn from healthy, Danish schoolchildren following an overnight fast. A ratio was calculated from serum leptin and adiponectin quantifications done using commercially available ELISA Kits. Results: Nine hundred eighty-three participants (583 girls) aged 6-18 years were included. Smoothed percentile curves and age-group specific percentiles were calculated. A correlation with age was demonstrated, with a gradual increase with age in girls and a negative parabolic relation, with a peak in age group 10-14, in boys. The leptin/adiponectin ratio was positively correlated to the body mass index standard deviation score for both girls and boys (p <.001). Conclusion: The leptin/adiponectin ratio is correlated to age and differs between the sexes in healthy children and adolescents