There are no data regarding adenosine levels in obese children, even though is a ubiquitous molecule implicated in the regulation of lipid metabolism in humans. To determinate whether adenosine plasma levels are related with anthropometric and biochemical markers in children, we studied 51 students belong to Ramon Belmar School in Linares, Chile. Review of clinical data and frequent food questionnaire were taken in order to collect the information. Plasma adenosine levels were measured by high-performance liquid chromatography and biochemical parameters including insulin, glucose, total proteins, and lipid profile by using standard colorimetric assays. Children with detectable (above 0.1 μM) adenosine plasma levels (n = 30; BMI, 22.3 ± 0.7) had higher total cholesterol (P < 0.05); triglycerides (P < 0.01) and LDL-cholesterol (P < 0.05) concentrations than children with undetectable adenosine levels (n = 21; BMI, 23.9 ± 0.61). Among the analyzed variables, only BMI and BMI standard deviation score (BMI-SDS) were positively correlated with adenosine levels. Besides, obese children (n = 10) showed significantly high adenosine levels compared to controls (n = 11; 1.8 ± 0.2 vs. 1.2 ± 0.1 μM/mg protein, respectively. P < 0.05), but not compared to overweight children (n = 9). In conclusion, obesity in children is associated to high adenosine plasma levels. This study opens a new perspective to investigate the role of adenosine in the regulation of lipid metabolism in obese children.